Identifying Sentence Errors

Correct Answer: B
Explanation:
The error in this sentence is (B): the verb "were" (which is plural) does not agree in number with the noun "thinking" (which is singular). The correct sentence reads: In the early twentieth century, new thinking about symbolism and the unconscious was greatly inspired by the writings of Sigmund Freud and Carl Jung.
(from the October 20, 1998 test)