The correct answer is option C. the movement of water from the central vacuoles of the cells into the solution.
Explanation:
In the given question onion cell was initially in 1% NaCl solution later student increase the concentration of the NaCl in the solution which makes the solution hypertonic.
A hypertonic cell is a solution with less water or more solute. Increasing salt concentration makes solute concentration high than inside the cell. Cell shrink in this case due to the osmosis or water movement from the high concentration region of water to the low concentration of water region.
