To find out how much Jamie spent on gas, you can multiply the number of gallons by the price per gallon.
So, you calculate:
\( 17 \text{ gallons} \times 2.79 \text{ dollars/gallon} = 47.43 \text{ dollars} \)
Therefore, Jamie spent $47.43 on gas to fill up her car.
The correct answer is D. $47.43.