The answer would be A. C stands for color and the (h) stands for height. The h is in parentheses because it is what changes and is then multiplied to the C. The C can only change when the h changes.
Goodluck with the quiz! :)
If I did everything correctly, It should be DEF.
Hope you get an A :d
You should definitely learn integration by parts.
Integration by parts becomes so useful, you'll even use it when you could do a simple u-substitution.
After integration by parts, I highly suggest learning trigonometric substitution. This helps you integrate expressions in a square root.