A non-metal that is found in a liquid state:
Bromine
The explanation for the correct option:
Non-metals have high electronegativity because they have a high tendency to accept electrons and acquire a negative charge and form an anion.
(A) Bromine is a nonmetal that exists in the liquid state at room temperature. But, physically most of the non-metals around us exist as gases, solids that are brittle and do not have a luster.
The explanation for the incorrect option:
Non-metals have high electronegativity because they have a high tendency to accept electrons and acquire a negative charge and form an anion.
(B) Iodine is non-metal that exists in a solid state at room temperature.
(D) Oxygen exists in a liquid state at room temperature.
(D) Carbon are nonmetals that exist in a solid state at room temperature.
Thus, option (a) i.e., Bromine is the correct option.