The correct answer is B. elated, accepted.
Santosh looked very happy and elated when he heard that his proposed scheme was accepted by the committee. This is because he was excited that his idea was approved and that he would be able to see it through. He was also likely feeling a sense of accomplishment and pride in his work.
The other options are not as likely to describe Santosh’s feelings in this situation. A. energetic is not a strong enough emotion to describe how happy Santosh was. C. satisfied is a more general term that could be used to describe how Santosh felt, but it does not capture the specific emotion of elation. D. disconsolate is the opposite of happy, and it is not likely that Santosh would feel this way if his scheme was accepted. E. overwhelming is a strong emotion that could be used to describe how Santosh felt if his scheme was rejected, but it is not as likely to be used to describe how he felt if it was accepted.