B. It was a time of economic hardship
ENGLISH
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Simple:
- he (think) ===> he thinks
- he (be) ====> he is
The sentence is thus 
He <u>thinks</u> that he <u>is</u> clever.
Learn more;work harder
#Carryonlearning
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FAlse, I think ask for other opinions too
May I ask what book and what are the answer choices?
The answer is B.) By explaining the rules of a Big Year