How many hooters shall be used for ART at the time of accident of a goods train outside the HQ. A. 2 B. 3 C. 4 D. 5

The correct answer is A. 2.

The ART (Accident Reporting and Treatment) procedure requires the use of two hooters to signal an accident. One hooter is sounded to alert the train crew, and the other is sounded to alert the dispatcher. The dispatcher will then dispatch a train to the scene of the accident to provide assistance.

Option B is incorrect because it would not provide enough warning to the train crew. Option C is incorrect because it would not provide enough warning to the dispatcher. Option D is incorrect because it is not necessary to use five hooters to signal an accident.