He went . . . . . . . . the park on his bicycle. A. around B. up C. under D. within

The correct answer is A. around.

The other options are not correct because they do not make sense in the context of the sentence.

• B. up: The park is not located on a hill, so it is not possible to go up the park.
• C. under: The park is not located underground, so it is not possible to go under the park.
• D. within: The park is not a small enclosed space, so it is not possible to go within the park.

The sentence “He went around the park on his bicycle” means that he rode his bicycle in a circular path around the park.