IMPROVE THE SENTENCE: One night they sank through the shiny water, and for the first time since "he has known them, began to quickly swim".

Options

A. A. he had known them, began to swim quickly.
B. B. he have known them, begin to quickly swim
C. C. he knew them, began to swim quickly
D. D. No Improvement

Answer

A

Explanation

Here, Past Perfect should be used.
Adverb (quickly) should come after Verb.
Hence, he had known them, began to swim quickly is the right usage.