Which is the best example of increasing entropy?

Transferring heat to a body.

Step by step

Entropy refers to the degree of disorder of a system. This increases when we move from a state of greater order to one of a greater degree of disorder.

By heating a body, this causes the energy of the body to increase. This means that the speed of the molecules that compose it increases and makes them collide more frequently between them, creating an increase in the degree of disorder that exists.

A clear example of heat transfer is when a body changes its state and moves from an orderly state to one of greater disorder.

 For example:

Melt an ice cube

Heat water until it starts to boil and turns into steam

You do not necessarily have to change the state to increase the entropy.

For example when heating water without boiling.

you'd use the equation that establishes a relationship between  energy  and  wavelength, which looks like this

e=h⋅cλ, where

λ  - the wavelength of the photon; c  - the speed of light, usually given as  3⋅108m/s; h  -  planck's constant, equal to  6.626⋅10−34j s

plug the value you were given for the energy of the photon in the above equation to get the wavelength

e=h⋅cλ⇒λ=h⋅ce

λ=6.626⋅10−34js⋅3⋅108ms−1.257⋅10−24j=1.581⋅10−1m