Correct Answer - A
(c ) Criticle angle,
sin C=`1/µ`
`therefore` `C=sin^(-1)(1/µ)`
and as µ decreases with increase in `lambda` yellow, orange, red have higher wavelength than green, so µ will be less for these rays, and so criticle angle for these rays will be high, hence, if green is just totally internally reflected than yellow, orange and red rays will emerge out.