To find out how many gallons of fuel Car A needs for a 140-mile trip, given that it has a fuel efficiency of 25 miles per gallon, you would use the formula:

$\text{Gallons needed} = \frac{\text{Total miles}}{\text{Miles per gallon}}$

Plugging in the numbers:

$\text{Gallons needed} = \frac{140}{25} = 5.6$

Thus, Car A needs 5.6 gallons of fuel for a 140-mile trip. The correct choice from the options is 5.6.

Would you like to understand more about how this calculation works, or do you have any other questions?

Here are five related questions:

1. How would the fuel requirement change if the car's efficiency were different?
2. What would be the distance that Car A could travel with 10 gallons of fuel?
3. How does fuel efficiency impact the cost of a trip if the price per gallon of fuel is known?
4. Can you calculate the amount of fuel needed for multiple cars on the same trip?
5. How does speed affect fuel efficiency?

Tip: When calculating fuel needs for a trip, always check if the distance you're traveling might require extra due to factors like traffic or detours, which can affect the actual fuel consumption.