Answer:
diverge light
Explanation:
The refractive index of water is greater than that of air which means that water is more denser than air and also air is optically rarer than water.
Thus,
When the beam of the light is incident from the air to the bubble which contains air, the light bends away from the normal and then the light travels from air to water and bend towards the normal. Thus, the light is first bend away from the normal and then towards the normal which means that the bubble has diverging nature. The light will likely to diverge.
A image is shown below for better understanding.
