How do the marginal propensity to save (MPS) and marginal propensity to consume (MPC) complement each other?

• A. They sum to 0, indicating no change in disposable income allocation.
• B. They sum to 1, indicating the total change in disposable income allocation.
• C. They are unrelated, indicating independent changes in disposable income allocation.
• D. They are equal, indicating identical changes in disposable income allocation.

Answer: (B)