Rain is falling vertically with a speed of $35 \mathrm{~m} \mathrm{~s}^{-1}$. Winds starts blowing after sometime with a speed of $12 \mathrm{~m} \mathrm{~s}^{-1}$ in east to west direction. At what angle with the vertical should a boy waiting at a bus stop hold his umbrella to protect himself from rain?
(a) $\sin ^{-1}\left(\frac{12}{35}\right)$
(b) $\cos ^{-1}\left(\frac{12}{35}\right)$
(c) $\tan ^{-1}\left(\frac{12}{35}\right)$
(d) $\cot ^{-1}\left(\frac{12}{35}\right)$