Answer:
The correct answer will be pipe.
Explanation:
Magma is a molten or partially molten mixture of rock-forming substances like water, sulfur, carbonates.
This flows out from the magma chamber due to the expanding force of the gases which pushes it to move out through a long tube which connects the magma chamber to earth surface called pipe until it explodes out through the vent.
Molten rock along with gases move through an opening called vent and leaves the volcano.
Thus, the pipe is the correct answer.
