A. The expression that could be used to determine the approximate number of hours it would take the rocket to travel from Earth to Mars is:
\[ \frac{3.39 \times 10^7 \text{ miles}}{3.6 \times 10^4 \text{ miles per hour}} \]
B. To find the number of hours, you would calculate:
\[ \frac{3.39 \times 10^7}{3.6 \times 10^4} \approx 942.5 \text{ hours} \]
So, it would take approximately 942.5 hours for the rocket to travel from Earth to Mars.
If you need to choose from specific options and "12,204" is the only one provided, please double-check the calculation as it seems incorrect based on the provided values.