The correct option is D 100.052∘C
Given : Kb=0.52 K kg mol−1, molality = 0.1 m
ΔTb=Kbm=0.52×0.1=0.052 K
Since, difference on kelvin scale and celsius scale is same, so ΔTb=0.052 K=0.052∘C
Hence, boiling point of solution =(Tb)H2O+ΔTb
=100∘C+0.052∘C
=100.052∘C