* Mark the letter A, B, C, or D on your answer sheet to indicate the most suitable response to complete each of the following exchanges.
Immediately after his arrival home a water-heater exploded.
A. Hardly had he arrived home than a water-heater exploded.
B. No sooner had he arrived home than a water-heater hadexploded.
C. Hardly had he arrived home when a water-heater exploded.
D. Scarcely he arrived home when a water-heater exploded.