Barbara used the distributive property to write an expression that is equivalent to 7 d + 63. Her work is shown below. The greatest common factor is 7 so 7 d + 63 = 7 (d + 63)

What was Barbara’s error?
Barbara wrote (d + 63) instead of 63 d).
Barbara wrote (d + 63) instead of (d + 9).
Barbara wrote (d + 63) instead of (d + 56).
Barbara wrote (d + 63) instead of (10 d).