Please help me with this question:

In your project you had planned to have Tasks A, B & C completed already, however tasks A, B, C, and D are 100%, 80%, 0%, and 0% complete respectively.
The value of each day of work is $100. Using the 0-100 Rule and the information given below, calculate the SPI:

Tasks A, B, C, and D have duration of 3, 5, 4, and 3 days respectively.

Ans. choices:

A. 0.25

B. 1

C. 0.50

D. 0.75