Choose the incorrect sentence from the sentences given below.

The correct answer is Option (3) → Mohan failed to do his satisfactorily work.

Adjective or adverb:

• An adjective describes a noun: satisfactory work.
• An adverb describes a verb: to work satisfactorily.
• This sentence: in "his satisfactorily work" an adverb stands before the noun "work". Either the adjective is used, "Mohan failed to do satisfactory work", or the adverb goes with the verb, "Mohan failed to do his work satisfactorily".
  Corrected: Mohan failed to do his work satisfactorily.
  Example: She finished the work satisfactorily.

Why the Other Options are Incorrect?

Option 1: His friend arrived at 2:00 p.m. — Incorrect. Correct use: "at" is the right preposition for a clock time.

Option 2: The stormy weather did not cause any trouble in the coastal regions of Tamil Nadu. — Incorrect. Correct use: "did not cause any" is the right negative form.

Option 4: His house has been burned down. — Incorrect. Correct use: the present perfect passive "has been burned down" is properly formed ("burnt" is also used).