Select the option that expresses the given sentence in direct speech.…

The correct answer is Option (3) → Neel said to his classmates, “Let us paint a mural on the canteen wall tomorrow.”

Changing a suggestion from indirect back into direct speech:

Change	Indirect	Direct	Why
Reporting verb	suggested to his classmates	said to his classmates	“Suggested to” goes back to “said to”. The suggestion now shows in the spoken words “Let us”.
Joining word	that	“ ” (quotation marks)	“That” is dropped. A comma and quotation marks come before the spoken words.
They should → Let us	they should paint	Let us paint	“They” means Neel and his classmates together, so it becomes “us”. “Should paint” becomes “Let us” + the plain verb “paint”. A mural is a large picture painted straight onto a wall.
Time word	the next day	tomorrow	Neel spoke of the day after he spoke. In his own words, “the next day” becomes “tomorrow”.
Full sentence	Neel suggested to his classmates that they should paint a mural on the canteen wall the next day.	Neel said to his classmates, “Let us paint a mural on the canteen wall tomorrow.”

“Should not” goes back to “Let us not” in the same way. Example: Ravi suggested that they should not waste water. → “Let us not waste water,” Ravi said.

Why the Other Options are Incorrect?

Option 1: Neel said to his classmates, “Let us to paint a mural on the canteen wall tomorrow.” — Incorrect. “Let” is followed by the plain verb, never by “to”. It must be “Let us paint”.

Option 2: Neel said to his classmates, “Let them paint a mural on the canteen wall tomorrow.” — Incorrect. “Let them” leaves Neel out of the plan. “They” in the report means Neel and his classmates, so it must be “us”.

Option 4: Neel said to his classmates that, “Let us paint a mural on the canteen wall tomorrow.” — Incorrect. “That” is kept before the quotation marks. Direct speech drops “that” and puts a comma before the spoken words.