Answer: Option (A) is correct.
Step-by-step explanation:
Given that,
Marginal propensity to consume (MPC) = 0.8
Increase in investment spending = $10 million
Marginal propensity to save (MPS) = 1 - MPC
= 1 - 0.8
= 0.2
Spending multiplier =

=

= $50 million
Therefore, If the MPC is .8 and there is a $10 million increase in investment spending, then the aggregate demand curve will shift up and to the right by $50 million.