If you save $$80$ when you experience a $$400$ rise in your income, A$)$ your MPS is $0\mathrm{.}25.$ C$)$ your MPC is $0\mathrm{.}85.$ B$)$ your MPC is $0\mathrm{.}80.$ D$)$ your MPS is $0\mathrm{.}40.$ Answer: B