Which of the following lines taken from page 121 of The Glass Castle, a novel by Jeannette Walls, has proper M.L.A. in-text citation formatting?

A. “As soon as she dropped us off, Dad disappeared. I waited on the front steps until bedtime, but he didn’t come home.” (Walls, 121)

B. “As soon as she dropped us off, Dad disappeared. I waited on the front steps until bedtime, but he didn’t come home” (Walls, 121).

C. “As soon as she dropped us off, Dad disappeared. I waited on the front steps until bedtime, but he didn’t come home” (Walls, 121)!

D. “As soon as she dropped us off, Dad disappeared. I waited on the front steps until bedtime, but he didn’t come home” (Walls 121).