For a total internal reflection, which of the following is correct?

Light travels from rarer to denser medium. Light travels from denser to rarer medium. Light travels in air only. Light travels in water only.

Light travels from denser to rarer medium.

Definition of TIR : Total internal reflection is a phenomenon of reflection of ray back to the same medium when passing from denser medium to rarer medium in a such away that angle of incidence greater than its critical angle.