Determine whether S is a basis for R^3.

S = {(2, 3, 4), (0, 3, 4), (0, 0, 4)}

A. S is a basis for R^3.
B. S is not a basis for R^3.

If S is a basis for R^3, then write u = (6, 6, 16) as a linear combination of the vectors in S. (Use s1, s2, and s3, respectively, as the vectors in S. If not possible, enter IMPOSSIBLE.)