Directions(21-25):Read each sentence to find out whether there is any grammatical error or idiomatic error in it. The error, if any, will be in one part of the sentence. The number of that part is the answer. If there is no error, the answer is (5). (Ignore errors of punctuation, if any)

After retiring she spent (1) / most of her time teaching young (2) / doctors and motivating themselves (3) /to work in rural areas. (4) / No error (5)