On the energy gain, answers b. and c. might give an energy gain, depending on the direction and strength of the gusts, but answer a. will definitely give an energy gain, a transient rise in IAS and an increase in lift. A. is the most correct answer.
Sea temp hardly changes night and day, so convective cloud remains the same. Answer b.
The 214 question implies that you are on a PPL exam. The national low level charts are not tested in the ATPL exam. You ought not to arithmetically average vector quantities like wind direction and strength, but on the 214 the spots are so close together that the adjacent wind directions only vary by a few degrees. In this case you can add the figures and divide by 2, either sideways or up and down. Do not, however, add wind directions of, say, 350 and 010 and find a mean direction of 180!!
Dick W