Fill in the blank with the most appropriate option in the following s…

The correct answer is Option (2) → let off

A phrasal verb is a verb joined with a small word such as up, out or together. The two words together have a new meaning.

Note: The given answer is as per the official NTA Answer Key. However, there appears to be a discrepancy in the key: the correct answer should be Option (4) → let up, as explained below.

Phrasal verb with "on":

• The blank is followed by "on her", so the phrasal verb must take "on".
• Let up on someone means to become less strict or severe with someone.
• This sentence: although Sharon complained and cried bitterly, Mom stayed firm. "Mom did not let up on her" says that Mom did not soften.
• Complete sentence: Though Sharon complained and cried bitterly, Mom did not let up on her.
  Example: The coach did not let up on the players even after the win.

Option 1: let in — Incorrect. To let in is to allow someone to enter. "Let in on her" makes no sense here. (To let someone in on a secret is to share it, which does not fit either.)
Example: Please let the cat in. It is raining.

Option 2: let off — Should be Incorrect. (But this is the correct answer in the NTA Answer Key.)

• To let someone off is to excuse them from a punishment or duty.
• It takes the person directly ("let her off"), not "on her", so "did not let off on her" is not standard English.
• The sentence could be reworded as "Mom did not let her off", but the blank as printed needs "let up".
  Example: The teacher let him off with a warning.

Option 3: let out — Incorrect. To let out is to allow someone to leave, or to make a sound such as a cry. It does not mean treating someone more gently.
Example: She let out a scream when she saw the snake.

Option 4: let up — Should be Correct. (Incorrect as per NTA) As explained above, "let up on her" means becoming less strict with her, which is what Mom refused to do in spite of the tears.
Example: The rain did not let up all night.

Advice for the exam: In the real exam, mark the answer that is grammatically or factually correct. If NTA’s provisional answer key marks a different option, challenge it during the answer-key challenge window and give the reason in one or two lines.