The correct answer is A.
Phenol on reaction with formaldehyde and dimethyl amine mainly gives Bakelite. Bakelite is a thermosetting plastic that is formed by the reaction of phenol and formaldehyde. The reaction is a condensation reaction, which means that water is eliminated as a byproduct. The reaction is catalyzed by acids or bases.
The first step in the reaction is the formation of a phenol-formaldehyde resin. This resin is a sticky, white solid. The next step is the curing of the resin. This is done by heating the resin to a high temperature. The curing process causes the resin to cross-link, which makes it hard and strong.
Bakelite is a versatile material that can be used to make a variety of products, including electrical insulation, cookware, and furniture. It is also used in the manufacture of some types of plastics.
The other options are incorrect because they are not formed by the reaction of phenol and formaldehyde.