Some of the sentence are grammatically correct and some are incorrect. Find which part of the sentence has an error and mark that part. If there is no error, mark that part as your answer
`("A major contribution of Mathura sculptors")/a` `("of that priod were the creation and popularization")/b` `("of the Buddha's image in humman form")/c` `("No error")/d`

Explanation

(b) Use .was. in place of .were.