Cook was a strict but good captain, _________ who, usually, took care of the sailors on his  ship

A.the one

B.one

C.that

D.this

答案及解析： B

解析：

考查同位语及定语从句。one 做a strict but good captain的同位语，并且做后面定语从句的先行词，句意：库克是一名严格而又和蔼的队长，他经常照顾他船上的船员们。所以选B。