Here Is a Consumption Function: C = C₀ + MPC(Y_d)

Here is a consumption function: C = C₀ + MPC(Y_d) .If C₀ = $200,then we know that

A) if Y_d is zero, C will be $200.
B) when Y_d rises, C rises by $200.
C) when Y_d falls, C falls by MPC times C₀.
D) C will always equal C₀.