Speaker: Like many contemporary critics, Smith argues that the true meaning of an author's statements can be understood only through insight into the author's social circumstances. ███ ████ ████ ████ ██ ████████ ███ ██ ███████ ██ ███████ ███ ██████ █████ ██ ███ ██ █████ ██ ██████ ██ █████ ██ █████ ██ █████ ██ ███████ ████ ███████ ██████ █████████████ ███ █████ ████████ ██ ███████ ███████████ █████ ██ █████ ████████ ████ █████ ███████ ██ ███ █████ ██ ███ ████ ███████ ██ ███ ███ ██████
The speaker concludes that Smith doesn’t understand the true meaning of her own words, because according to Smith (who we are allowed to assume is correct), understanding true meaning requires insight into social circumstance.
The conclusion is Smith’s failure to understand, and we have a conditional describing what is necessary to understand. We need to know that Smith has failed this requirement to conclude that she does not understand.
The speaker's main conclusion logically ███████ ██ █████ ███ ██ ███ █████████ ██ ████████
Insight into the ████████ ███████ ██ ██ ████████ ████ ██ ███ ██ █████████ ██ ███████ ████ ███ ████ ████████
We are not trying to compare importance of anything. We need airtight support that Smith doesn’t understand her own words. Also, we cannot use information about intended meaning to validly support any conclusion here.
Smith lacks insight ████ ███ ███ ██████ ██████████████
If this is true, then Smith has failed the requirement for true understanding. We can validly draw the conclusion that she doesn’t truly understand her own words.

There is just ███ ███████ ████ █████ ███████ ███ ████ ██ █████
Having more than one meaning doesn’t affect this argument for better or worse. We are trying to conclude that Smith doesn’t understand her own words.
Smith's theory about ███ ████████ ██ ██████ █████████████ ██ ███ █████████████ ██ ███████ █████ ████████
This is attempting to undermine Smith’s theory, but the speaker’s argument actually hinges on Smith being correct. He has also given us permission to treat it as true, i.e. “Thus, if she is right...”
The intended meaning ██ ██ ████████ ████ ██ ███ ██████ ████ ████████ ██ ███ ████ ████████
We cannot use this to validly draw any kind of conclusion. Like (A), this answer is introducing intended meaning, but there is no information about intended meaning in the argument.