The correct answer is B). The potato cells lost water to the surroundings.
The salt water solution is hypertonic as compared to cell of a potato slice. In other words cells of potato slice is hypotonic to salt solution. Water always moves from hypotonic to hypertonic solution if they separated by semipermeable membrane. Thus, when potato slice is dipped into salt water, ex-osmosis that is water will move out of the potato slice into the salt solution. As a result into shrinking of potato slice.
In one class of response, B cells secrete antibodies that neutralize the virus.
