The answer for the problem shown in the figure attached, is the option B, which is:
B) f(x)=(-y/x)^5
The explanatio for the exercise is shown below:
1. You have the following function given in the problem above:
f(x)=-(x/y)^-5
2. The negative exponent -5, indicates that the x must be in the denominator and the y must be in the numerator, and the exponent must be positive as following:
f(x)=(-y/x)^5