\((A)\) will be:

The correct answer is option 3.

The reaction will be as:

Diethyl ether is formed by the nucleophilic substitution reaction. When ethanol is treated with a second mole of ethanol in the presence of sulphuric acid, diethyl ether is formed by the dehydration process of one of the ethanol molecules.

The reaction occurs as shown below:

In this reaction, the mechanism is followed by the dehydration of ethanol molecules followed by unimolecular nucleophilic substitution reactions. First, the ethanol is treated in the presence of any acid \((H_2SO_4)\) which can give proton. So the water molecule is eliminated from ethanol and carbocation is generated. Now, the second molecule of ethanol will act as a nucleophile and attacks at the electrophilic carbon this process is known as unimolecular nucleophilic substitution. After this step we will get our final product as diethyl ether as shown in the above mechanism.