Correct option is (a) y=7x^2
Easiest explanation: Consider the function y=7x^2
Differentiating w.r.t x, we get
\(\frac{dy}{dx}\)=14x
∴\(\frac{dy}{dx}\)-14x=0
Hence, the function y=7x^2 is a solution for the differential equation \(\frac{dy}{dx}\)-14x=0