The correct option is C Ether
An important laboratory method used for the preparation of symmetrical and unsymmetrical ethers is Williamson synthesis. In this method, an alkyl halide is allowed to react with sodium alkoxide to form ethers.
So, heating of sodium ethoxide and ethyl chloride together will give diethyl ether.
CH3CH2ClEthyl chloride+CH3CH2O−Na+Sodium ethoxide→CH3CH2−O−CH2CH3Diethyl ether+NaCl
So, the correct option is (a)