Self-study
Support If the budget does not allow for more dairy inspectors to be hired, most of the large dairies in the central valley will not meet federal standards governing the disposal of natural wastes, which can seep into streams and groundwater. ███ ███ ████████ ███████ ████████ ████ ███ █████ ███ ███ ██████ ██ ████ █████ ███████████ █████████████ ████ ██ ███ ██████████ ████████ █████ ██ ██████ ██ ██████ █████████
Summary
The author concludes that most of the district’s drinking water is likely to become polluted. This is based on the fact taht the new district budget doesn’t allow for hiring of more dairy inspectors, and if that’s the case, then most large dairies in the central valley will not meet federal standards.
Missing Connection
The premises allow us to conclude that most large dairies in the central valley won’t meet federal standards. But how do we get from this inference to the conclusion that most of the district’s drinking water is likely to be polluted? We want to supply the following relationship:
If most large daries in the central valley don’t meet federal standards, then most of the district’s drinking water is likely to be polluted.
22.
The conclusion above follows logically ██ █████ ███ ██ ███ █████████ ██ ████████
a
If most of ███ ███████ ██ ███ ███████ ██████ ████ ███████ █████████ ███ ███ ████████ ██ ███████ ███████ ██ ██ ████████ ████ ████ ██ ███ ██████████ ████████ █████ ████ ██████ █████████
We’re looking for the claim that if most of the dairies in the central valley DON’T meet federal standards, it’s likely that the water WILL be polluted. (A), however, tells us what happens if most of the dairies DO meet federal standards. This doesn’t establish what happens if most of the dairies DON’T meet federal standards.
b
To keep all ███ ████████ █████ ██ ███ ████████ █████ ████████ ████ █████ ██████████ ██ ███████ ███ ████████ ████████ ██ ███████ ███████
Even if (B) could establish that we can’t keep “all” of the drinking water clean, this doesn’t guarantee that “most” of the drinking water is likely to be polluted. For example, perhaps only 1% of the water is unclean. This wouldn’t be a situation in which most (over half) of the drinking water is polluted.
c
All of the ██████████ ████████ █████ ██ ██████ ██ ██████ ████████ ████ ██ ███ ██ ███ █████ ███████ ██ ███ ███████ ██████ ██ ███ ████ ███████ █████████ ███ ███ ████████ ██ ███████ ███████
(C) reverses something that would be correct. “Only if” introduces a necessary condition. But we want to know that failure to meet federal standards is sufficient to make most of the drinking water likely to be polluted.
d
Most of the ██████████ ████████ █████ ██ ██████ ██ ██████ ████████ ██ ████ ██ ███ █████ ███████ ██ ███ ███████ ██████ ██ ███ ████ ███████ █████████ ███ ███ ████████ ██ ███████ ███████
We know from the premises that most large dairies in the central valley don’t meet federal standards. (D) tells us that if that is the case, most drinking water is likely to be polluted. 
e
If none of ███ █████ ███████ ██ ███ ███████ ██████ █████ ███████ █████████ ███ ███ ████████ ██ ███████ ███████ ████ ██ ███ ██████████ ████████ █████ ██ ██████ ██ ██████ █████████
We do not know from the premises that “none” of the large dairies in the central valley meet federal standards. So the premises would not interact with the conditional in (E). We still would not know whether most of the drinking water is likely to become polluted.