यदि `a cos theta + b sin theta = m` तथा `a sin theta - b sin theta = n ` हो , तो `a^2 +b^2` का मान है

Options

A. `m^2 -n^2`
B. `m^2 n^2`
C. `n^2 - m^2`
D. `m^2 +n^2`

Answer

D