Why do we see water droplets on the outer surface of a glass containing ice-cold water?

Due to Condensation

The correct answer is option 1. Due to Condensation.

When ice-cold water is taken in a tumbler, soon we will see water droplets on the outer surface of the tumbler.

The water vapour present in air, on coming in contact with the cold glass of water, loses energy and gets converted to liquid state, which we see as water droplets.

The process of conversion of gaseous state into liquid state is called condensation.