A) The catalytic hydrogenation of an alkyne to alkene does not stop at alkene stage but continues further to alkane stage.
B) Reagent such as Lindlar's catalyst is used to convert alkyne to alkene but it gives cis product.
C) $LiAlH _{4}$ does not reduce double bond of alkynes.
D) $Li / NH _{3}$ is birch reagent and it reduces alkyne to trans alkene.