To find your earnings per hour, you can divide the total earnings by the number of hours worked.
You earned $280.00 for working 40 hours.
So, the calculation is:
\[ \text{Earnings per hour} = \frac{\text{Total earnings}}{\text{Total hours}} = \frac{280.00}{40} = 7.00 \]
Thus, your earnings per hour are $7.00.
The correct answer is B. $7.00.