In Order to Calculate the APR for an ARM,you Must

In order to calculate the APR for an ARM,you must,

A) only use the first year's given interest rate.
B) estimate interest rates over the life of the loan.
C) assume the worst case scenario and use interest rates at their highest possible point over the life of the loan.
D) use only the first five year's interest rates because they can easily be estimated and most people only own a property for five years.