A metal string is fixed between rigid supports. It is initially at negligible tensin. Its Young modulus is `Y`, density `rho` and coefficient of thermal expansion is `alpha`. If it is now cooled through a temperature `=t`, transverse waves will move along it with speed
A. `Ysqrt(alphat//rho)`
B. `alphatsqrt(Y//rho)`
C. `sqrt(Y alpha t//rho)`
D. `t sqrt(Yalpha//rho)`
