Depot in-charge is responsible to test the detonators once in ________. A. Monthly B. Weekly C. Year D. None of these

The correct answer is: A. Monthly.

The depot in-charge is responsible to test the detonators once in a month. This is to ensure that the detonators are in good working condition and that they will function properly when needed. The depot in-charge should also keep a record of the test results and make sure that they are properly documented.

Option B is incorrect because detonators should be tested more frequently than once a week. Option C is incorrect because detonators should be tested more frequently than once a year. Option D is incorrect because the depot in-charge is responsible to test the detonators once in a month.