The correct answer is C. 150 kg/m2.
A live load is a load that is not permanently attached to a structure and may vary in position and magnitude from time to time. Accessible roofs are roofs that are designed to be used by people, such as for walking, working, or storage. The live load for an accessible roof is typically 150 kg/m2, which is equivalent to 15 psf. This load is based on the assumption that people will be walking on the roof and that there may be some equipment or furniture stored on the roof.
Option A is incorrect because it is the live load for a roof that is not accessible. Option B is incorrect because it is the live load for a floor. Option D is incorrect because it is the live load for a column.