Answer:
D: combined
Explanation:
Given the equation of variation:
[tex]f=\frac{kw_1w_2}{s}[/tex]We see that f varies jointly with w1 and w2; f also varies inversely with s.
A situation where one variable depends on two (or more) other variables, and varies directly with some of them and varies inversely with others is referred to as a Combined Variation.
The variation is combined.
Option D is correct.
