Directions: The following sentence tests your ability to recognize grammar and usage errors. The sentence contains either a single error or no error at all. If the sentence contains an error, select the underlined part that must be changed to make the sentence correct. If the sentence is correct, select option (E). While choosing the answer, follow the requirements of standard English.

(A) Six weeks later, he (B) returned with (C) knowledge enough to teach (D) others the tricks of the trade. (E) No error