Answer:
B
Explanation:
This is a simple interest problem. The formula for simple interest is:

Where
i is the interest amount
P is the principal amount
r is the rate of interest
t is the time in years
Given P, r, and t, we need to find convert r (as a percentage) to a decimal. We simply divide by 100. Shown below:
r = 7% = 7/100 = 0.07
Now, we substitute into formula and find i (interest):

Correct answer is B, $42