When zinc metal reacts with sodium hydroxide solution on heating, the gas evolved:
Burns with a pop sound
The explanation for the correct option
(C) burns with a pop sound
The reaction of zinc with sodium hydroxide
Zinc reacts with sodium hydroxide to form sodium zincate and hydrogen gas.
Hydrogen gas burns with a pop sound.
Explanation of the incorrect options
(A) turns lime water milky
Hydrogen gas does not turn lime water milky.
(B) supports combustion
Hydrogen gas does not support combustion.
(D) has a pungent odor
Hydrogen gas is odorless.
As when zinc reacts with sodium hydroxide, hydrogen gas is made which burns with a pop sound.
Hence, the correct option is (C).