You are towing a 1,000 GT gasoline tank barge which is not gas free. By regulation, cargo tank hatches, ullage holes, and Butterworth plates on the barge may ___________________.

A
not be open without flame screens under any circumstances
B
be open without flame screens in good weather from 16 May to 15 September
C
be open without flame screens when the barge is empty
D
be open without flame screens under the supervision of the senior crew member on duty
E