The correct answer is option 1: 10.00.

The marginal propensity to consume (MPC) is the proportion of additional income that is spent on consumption. In this case, with an MPC of 0.90, it means that for every additional unit of income, 90% of it will be spent on consumption.

The multiplier effect refers to the impact of an initial change in spending on the overall level of economic activity. It measures how much aggregate demand will change as a result of an initial change in spending.

The formula to calculate the multiplier is 1 divided by the marginal propensity to save (MPS), which is the proportion of additional income that is saved rather than consumed. In a closed economy with no taxes, the sum of MPC and MPS is always equal to 1 (MPC + MPS = 1).

Since the question states that the MPC is always 0.90, we can calculate the MPS as 1 - MPC = 1 - 0.90 = 0.10.

Now, to calculate the multiplier, we divide 1 by the MPS: 1 / 0.10 = 10.

Therefore, the value of the multiplier, in this case, is 10.00. This means that for