In a fire fighting machine, a jet is attached to the head of water pipes to increase the

Explanation

The correct answer is Option C: The jet is designed to increase the velocity of water flowing out of it. By constricting the flow path, the jet causes the water to exit at a higher speed, which is essential for reaching greater distances and effectively fighting fires. Option A is incorrect because the mass of water is determined by the source and does not change with the use of a jet. Option B is incorrect as the volume of water is determined by the supply, not by the jet. Option D is partly correct in that the distance can be increased, but this is a result of increased velocity, which is why Option C is the more direct and accurate answer.