c
Velocity of sound in air $\left( V \right) = \sqrt {\frac{{\gamma RT}}{M}} $
$ \Rightarrow {V^2}\alpha T$ (in kelvin)
not ${V^2}\alpha T$ (in ${\,^0}C$)
Hence $(B)$ is incorrect.
velocity of transverse wave in nastring
$V = \sqrt {\frac{T}{\mu }} = {V^2}\alpha T$