You have to make sure that the answer is entirely correct. So you are right that the fact that there is only one example does come into play, as the answer does say "examples." But you have to ask yourself - in connection with choice C - does the author really seek to demonstrate the effe...

That's the problem -- it's not asking anything. There's no "question" at the end of the paragraph. If it was a fill in the blank, then the answer choices would make a complete sentence with the last sentence of the passage, but they don't. Here's the complete last sentence: Therefore, onc...

Less than 35 years after the release of African honeybees outside Sao Paulo, Brazil, their descendants, popularly known as killer bees, had migrated as far north as southern Texas. (A) Less than 35 years after the release of African honeybees outside Sao Paulo, Brazil, (B) In less than 35 years sin...