Suppose a quantilty x can be dimensionally represented in terms of M,L and T, that is `[x], M^aL^bT^c`. The quantity mass

A. can always be dimensionally represented in terms of `L, T` and `x`

B. can never be dimensionally represented in terms of `L, T` and `x`

C. may be represented in terms of `L, T` and `x` if `a = 0`

D. may be represented in terms of `L, T` and `x` if `a != 0`