To find the cost per gallon of gasoline, you can divide the total amount paid by the total number of gallons.
Sora paid $26.46 for 8.4 gallons.
Cost per gallon = Total amount paid / Total gallons
Cost per gallon = $26.46 / 8.4
Now, let's calculate it:
\[ Cost\ per\ gallon = \frac{26.46}{8.4} \approx 3.15 \]
Therefore, each gallon of gasoline cost approximately $3.15.
The correct answer is $3.15.