Final answer:
The correct word to complete the statement "Cooper's _____ bet that he could not write a better novel than the one he was reading" is d. "gamble".
Step-by-step explanation:
In the context of the given sentence, the most suitable word to complete the statement is "gamble". The sentence talks about someone wagering that Cooper could not write a better novel than the one he was currently reading. This kind of challenge or bet usually implies a sense of risk-taking, which is best encapsulated by the noun "gamble".
While "contention" could potentially fit, it is used more to describe a dispute or argument rather than a bet. "Prowess" refers to skill or expertise, which does not fit the context of betting or challenging. "Bluff" is typically used to describe a false display intended to deceive, which is not appropriate in the context of this sentence.
Therefore, the correct option in the final answer is d. Gamble. By choosing "gamble," the sentence correctly implies that there was a risk associated with the challenge of writing a better novel.