In each of the following question, a statement of Assertion (A) is given followed by a corresponding statement of Reason (R). Choose the correct answer as:

Assertion (A): H₂O is the only hydride of chalcogen which is liquid at ordinary temperature.

Reason (R): In ice, each O atom is surrounded by two covalent bonds and two H-bonds.

If both assertion and reason are true, but the reason is not the correct explanation of the assertion.

H_2​O is only the hydride of group 16 elements  which is liquid at ordinary temperature, whereas all others gases.
In ice, each H₂​O molecule oxygen is held by two covalent bonds with two hydrogen atoms and two hydrogen bonds with two other water molecules. So both assertion and reason are correct but reason is not the correct explanation for assertion.