He only wrote (a)/on one side (b)/of the paper(c)/No error (d)

https://things-for-students.blogspot.com/2022/05/he-only-wrote-aon-one-side-bof-papercno.html
He only wrote (a)/on one side (b)/of the paper(c)/No error (d) 1.(a) 2.(b) 3.(c) 4.(d) Correct Answer: a ["wrote only" should be used in place of "only wrote"]