Find the part of the given sentence that has an error in it. If there is no error, choose 'No error'.
The muscles on his chest and arms was not well defined.

The correct answer is (d) was not well defined.
Explanation:
The error in this sentence lies in subject-verb agreement. The subject is "muscles," which is plural, so the verb should be "were" instead of "was." The correct form is "were not well defined."
Corrected sentence:
The muscles on his chest and arms were not well defined.
Meanings of all options:
· No error: This option is incorrect as there is a subject-verb agreement error.
· The muscles on: This part is grammatically correct.
· His chest and arms: This part is also grammatically correct.
· Was not well defined: Incorrect verb agreement; "was" should be replaced with "were."