Correct Answer: Just before the deadline

Solution : The fourth option is correct.

This idiom is derived from the biblical parable of the labourers in the vineyard, where workers were hired throughout the day, but those hired at the eleventh hour received the same payment as the others. Over time, the phrase has evolved to mean doing something at the last possible moment or just before a crucial deadline. So, just before the deadline best captures the intended meaning of the idiom.

Therefore, the correct answer is: Just before the deadline.