Assertion. C-H bond in ethyne is shorter than C-H bonds in ethene.
Reason. Carbon atom in ethene is sp hybridised while it is `sp^3` in ethyne.
A. If both assertion and reason are true, and reason is the true explanation of the assertion.
B. If both assertion and reason are true, but reason is not the true explanation of the assertion.
C. If assertion is true, but reason is false.
D. If both assertion and reason are false