托福词汇猜测题之peak

　　After the peak year of 1957, the birth rate in Canada began to decline. It continued falling until in 1966, it stood at the lowest level in 25 years.

　　The word "peak" is closest in meaning to which of following?

　　(A) pointed

　　(B) dismal

　　(C) mountain

　　(D) maximum