Answer: 
<u>Step-by-step explanation:</u>
The general form of a sin/cos function is: y = A sin/cos (Bx-C) + D where the period (P) = 2π ÷ B
In the given function,
→ 
Half of that period is: 
Calculate the period for each of the options to find a match:

Inverse Property, I am pretty sure. Not sure though.
Given:

Sol:
Area of picture is:

If the cost $10 per square inch then price of 15 square inch is:

If the quadruple of dimension that mean:

So area is:

So price is: