`CH_(3)-C-=CH overset(dil H_(2)SO_(4)) underset(Hg^(2+))to underset("(X)")(CH_(3)-overset(OH)overset(|)(C)-CH_(2)) harrunderset("(Y)")(CH_(3)-overset(O)overset(|)(C)-CH_(3))`
By what phenomenon X converts into Y.
A. Isomerisation
B. Aromatisation
C. Tautomerism
D. Metamerism.