The correct answer to the question is that water will exert a force on the swimmer in forward direction, and swimmer will move along that direction.
EXPLANATION:
Before going to answer this question, first we have to understand Newton's third laws of motion.
Newton's third laws of motion states that, for every action, there is an equal and opposite reaction.
In the given question, the swimmer pushes the water in backward direction. This is the force of action. As per Newton's third law, the water must exert a reaction on the swimmer. The water applies a force on the swimmer in forward direction for which the swimmer can swim in the water.
