If $$x \neq y$$​, and $$x^2y - xy^2 : yz(x-y) :: xa^2 - xb^2 : w$$​, then which of the options below gives an expression equivalent to $$w$$​?

Correct option is A

Given:  

​$$x^2y - xy^2 : yz(x-y) :: xa^2 - xb^2 : w$$ 

Solution: ​

​$$x^2y - xy^2 : yz(x-y) :: xa^2 - xb^2 : w \\ \ \\ \frac{ x^2y - xy^2} { yz(x-y)} = \frac{xa^2 - xb^2} w \\ \ \\ \frac{ xy(x - y)} { yz(x-y)} = \frac{x(a^2 - b^2)} w \\ \ \\ \frac{x}{z} = \frac{x(a^2-b^2)}{w} \\ \ \\ \implies w = z(a^2 -b^2) \\ \ \\ w = za^2 -zb^2$$​​