Correct Answer - C
Critical angle between glass and liquid face is
`sintheta_(c)=(3//2)/(mu)=(3)/(2mu)` ....(1)
Angle of incidence at `AC` is `60^(@)`
i.e., `i=60^(@)`
For total internal refelction to take place
or `sin i gt sin theta_(c)`
or `sin60^(@)gt(3)/(2mu)`
or `(sqrt(3))/(2)gt(3)/(2mu)`
or `mgtsqrt(3)`