The correct option is A Li/LiqNH3,H2/Lindlar's catalyst
'X' and 'Y' are Li/LiqNH3,H2/ Lindlar's catalyst respectively.
Li/LiqNH3 reduces 2−butyne to trans−2−butene (A).
H2 Lindlar's catalyst reduces 2−butyne to cis−2−butene (B).
trans−2−butene is more symmetrical than cis−2−butene as trans−2−butene has inversion centre which is not present in cis−2−butene.
cis−2−butene has higher heat of hydrogenation than trans−2−butene.