Correct Answer - C
The elevation `(Delta T_(b))` in the boiling point `= 354.11 K - 353.23 K = 0.88 K`
Substituting these values in expression
`M_("Solute")=(K_(b)xx1000xxw)/(Delta T_(b)xx W)`
Where, w = weight of solute, W = weight of solvent
`M_("solute")=(2.53xx1.8xx1000)/(0.88xx90)=58 gm mol^(-1)`
Hence, molar mass of the solute `= 58 gm mol^(-1)`