Among the four alterative, choose the one which can be substituted for the given sentence.
A person who insists on something

Correct option is B

The correct answer is (b) Stickler.
Stickler: A person who insists on strict rules or principles. Stickler in Hindi: नियमों का सख्ती से पालन करने वाला व्यक्ति। Example: He is a stickler for punctuality and never tolerates delays.
Meanings of other given options:
· Boaster: A person who brags ( Example: He is a boaster who always talks about his success).
· Instantaneous: Happening immediately ( Example: The reaction was instantaneous).
· Disciplinarian: A person who enforces strict discipline ( Example: The teacher was a strict disciplinarian).