Which of the following show an increase in entropy?

I. Boiling of water

II. Melting of ice

III. Freezing of water

IV. Formation of hydrogen gas from water

Entropy is the measure of disorderliness. It means as disorderliness increases entropy increases.

Melting of ice leads to the formation of liquid water where the particles are in random motion which leads to an increase in entropy.

Option (c) is the correct option as in $\left(\mathrm{i}\right),\left(\mathrm{ii}\right)$ and $\left(\mathrm{iv}\right)$ the state changes towards more random state, thus entropy increases.