Find the general solution to the following problem:
uₜt = c² * (1/r * ∂/∂r(r ∂u/∂r) + 1/r² * ∂²u/∂θ²), 0

a) u(r,θ,t) = f(r) + g(θ) + h(t)
b) u(r,θ,t) = R(r) + Θ(θ) + T(t)
c) u(r,θ,t) = R(r)Θ(θ)T(t)
d) None of the above