The angle of contact at the interface of water-glass is `0^(@)`, Ethylalcohol-glass is `0^(@)`, Mercury-glass is `140^(@)` and Methyliodide-glass is `30^(@)`. A glass caplillary is put in a trough containing one of these four liquids. It is trough containing one of these four liquids. It is observed that the meniscus is convex. The liquid in the through is
A. Water
B. ethylalcohol
C. mercury methyliodide.
D.