What most likely caused the water to rise in and erupt from the vent

The correct answer is heating of water by the hot rocks or the magma.

Explanation:

The eruption of water from the vents is a result of the geologic activity taking place within the Earth. The water present deep within the ground gets heated up by the hot rocks or the magma, leads to an elevation in the pressure, and as a consequence shooting of water takes place up in the air, that appears like vents are erupting.

The majority of the vents are witnessed in the regions, which are near to a volcano or are associated with a volcano via underground channels.

Im gonna say heat is what forced the water to rise and erupt.