Given below are sentences with an idiom given in bold. Replace the idiom from the four options provided to make the sentence contextually meaningful and grammatically correct. If no such replacement is required mark (e)
i.e., “No replacement required” as your answer choice. Even though he had failed multiple times, he was determined to call it a day and keep trying until he succeeded.

The idiom "call it a day" means to stop trying or give up, which contradicts the sentence's meaning of continuing to try despite failures. "Stay the course" means to persist with an effort or goal despite difficulties, which fits the sentence context better. Meanings of other idioms: Bite the bullet – To endure a painful or unpleasant situation. Weather the storm – To survive a difficult or challenging period. Throw in the towel – To give up, stop trying (closer to the meaning of "call it a day," but opposite in intent). Since the sentence emphasizes determination to keep trying, option (a) is the correct choice.