Task: Question Answering
Input (English): If \(ab = k\), \(b = ka\),and \(k \neq 0\), which of the following could be equal to \(a\)?
(A)0 (B)\(\frac { 1 } { 2 } \) (C)1 (D)b (E)\(\frac { 1 } { b } \)
Output (English): C