The correct option is D kidnapped
The word "ransom" gives us a clue. A ransom is the money (Rs 8, 000) that has to be paid to the kidnapper (here, "servant") so that he will set free the person kidnapped (here, the "five-year-old boy"). Hence option D is correct.
Option A - Driven means is the past participle of drive which could be a simple task for a servant.
Option B- Arrested is the past participle of arrest which means to stop pr prevent.
Option C - Escorted means to accompany.
Hence options A, B and C are incorrect.