If the Reaction 3A + B + C $\rightarrow$ 2D + E Is First Order Overall, Which of These

If the reaction 3A + B + C $\rightarrow$ 2D + E is first order overall, which of these could be the units of its rate constant, k?

A) 1/s
B) M/s
C) 1/Ms
D) 1/Ms²
E) Ms