Choose the correct indirect transformation of the following sentence…

The correct answer is Option (2) → Rahul said that he must go then.

Direct	Indirect
Rahul said, "I must go now."	Rahul said that he must go then.

Statement in indirect speech:

• Reporting verb: "said" (with no object) stays "said", and that joins the reported statement; the inverted commas are dropped.
• Tense change: must (necessity) has no past form of its own, so it usually stays must (it may also become "had to").
• Pronoun changes: "I" → he (Rahul, the speaker).
• Words of nearness (time and place): "now" → then.
• Other standard changes: is/am → was, do/does → did, will → would, can → could, may → might, has/have → had, here → there, today → that day, tomorrow → the next day.
  Example: She said, "I must leave now." → She said that she must leave then.

Why the Other Options are Incorrect?

Option 1: Rahul said he has to go then. — Incorrect. "has to" is present tense; after the past reporting verb "said", must stays must or becomes had to.

Option 3: Rahul said that he must go now. — Incorrect. "now" is not changed to "then"; words of nearness change in indirect speech.

Option 4: Rahul said that he should be going then. — Incorrect.

• "should" (advisability) changes the meaning of must (necessity).
• The continuous form "be going" is not in the original.

Contrast: "must" can stay unchanged after "said", but the time word "now" changes to "then".