With an increase in marginal propensity to consume the value of investment multiplier will :

Increase

The correct answer is option (1) : Increase

The Multiplier Formula:  Multiplier = 1 / (1 - MPC)

Impact of MPC:

As the MPC increases (more consumption from each additional income), the value in the denominator (1 - MPC) gets smaller. This results in a larger value for the multiplier.

Relationship: A higher multiplier signifies a greater impact on national income from a change in investment. So, an increase in MPC leads to a stronger multiplier effect.