Read the sentence and decide which answer A, B, C or D best fits the space and completes the idiom. Harry couldn't stand his superiors... and stick approach, so he quit his job.…

The correct answer is A. "carrot." The idiom is "carrot and stick," which refers to a method of motivation that uses rewards (the carrot) and punishment (the stick). The completed sentence would be: "Harry couldn't stand his superiors' carrot and stick approach, so he quit his job."