NASA is giving serious consideration to the concept of solar sailing. A solar sailcraft uses a large, low mass sail and the energy and momentum of sunlight for propulsion. (a) Should the sail be absorbing or reflective

Reflective

Explanation:

The radiation pressure of the wave that totally absorbed is given by;

and While the radiation pressure of the wave totally reflected is given by;

Now compare the two-equation you can clearly see that the pressure due to reflection is larger than absorption therefore the sail should be reflective.

d is the answer i came up with