Xin Co., had 3,000 units of work in process on April 1 that were 60% complete. During April, 10,000 units were completed and as of April 30, 4,000 units that were 40% complete remained in production. How many units were started during April?

(A) 8,600.
(B) 9,800.
(C) 11,000.
(D) 12,200.
(E) None of the answers is correct.