Answer:
D
Explanation:
In an ordered pair, the input is the first value, and the output is the second value.
The input, x, in this case equals 3p, so that will be our first value, which eliminates answers A and B.
Now to find the output, simply plug the input into all instances of x in the equation, like so:
Resolving that, we get 3p + 4 as our second value, which combined with our first value gets us (3p, 3p+4), which is answer D.