The leader failed to explain the cause of the problem. He did not offer any solutions.
A. Though the leader failed to explain the cause of the problem, he did not offer any solutions.
B. Because the leader failed to explain the cause of the problem, he did not offer any solutions.
C. The leader failed to explain the cause of the problem nor did he offer any solutions.
D. Because the leader did not offer any solutions, he failed to explain the cause of the problem