Which expression is dimensionally consistent with an expression that would yield a value for time−1? (v is velocity, x is distance, and t is time)

Which expression is dimensionally consistent with an expression that would yield a value for time−1? (v is velocity, x is distance, and t is time)

A. v/x

B. v2/x

C. x/t

D. v2t

The answer is :

A. v/x