In the question below, three statements are given which may or may not contain an error in any part of the sentence. Identify the statements containing an error and also point out the part containing the error.

I. The conference (a) room had (b) been cleaned  (c) before they arrived. (d)

II. The teenagers have (a)been up watched (b) movies all night (c) and day. (d)

III. He agree (a) to start (b)his work on the project (c) related to science and technology. (d)