How is "that" an object?

I figured it wasn't B bc the stimulus says "almost all" and "unlikely" so it is not saying all corporations do this by using this phrasing. Is that another way of looking at it?

Question 4: Why isn't the subject noun hurricanes and the predicate-verb threaten.

Question 2: I thought "the concept" modified developed, rather than being an object

Similarly, for Q3: I thought "billboards are the basis of our business" modified declared.

for sentence 4, why isn't scientists the noun (I thought it was bc "who" is right after it), but it does say "who" is often, not always used as a noun modifier.