Find the solution, M(t), of the differential equation dM/dt = r(k - rM) in terms of k and r.
a) M(t) = (rk / r - M)e^(rt)
b) M(t) = (rk / r + M)e^(-rt)
c) M(t) = M(e^(-rt) + rk)
d) M(t) = (M + rk)e^(-rt)