Hi there! The answer is D.
The parent function is the simplest form of a function. We can distinguish a variety of parent functions like linear, exponential, square root, absolute, logarithmic, quadratic, cubic, rational or constant (trigonometric functions excluded).
Now we can have a look at the function.

The thing that is the most important in this function is the square root, because this mainly decides the way the function looks. Therefore, the parent function is the simplest form of a square root function, which is the following:

Therefore the answer is D.
~ Hope this helps you!
To find the cost per pound you simply divide the amount paid by the amount purchased
For Beef it would be:
$7.20 ÷ 2.0 = $3.60
For Pork it would be:
$8.10 ÷ 2.5 = $3.40
For Chicken it would be:
$9.80 ÷ 3.5 = $2.8
:)
x+x+55+x+38=180
3x+93=180
3x=87
x=29°