Plasmolysed because of osmosis as the salt solution has lower water potential than the cells of the stalk
According to the cooling curve given above, at temperature 275K, the phases that will be observed is LIQUID AND SOLID.
The flat points on the graph represent the points where phase changes are taking place.The beginning of the first flat point represent the point where the gas become liquid, the extreme end of this point indicate the point where the liquid has started turning to liquid and that is the point of 275K. Thus at that point both phases are present.
Answer: He could add a base to the pool to neutralize the acid.
Explanation:
Chlorine is used to disinfect the pools as it produces hypochlorous acid in water. This hypochlorous acid is unstable and gives hydrochloric acid and nascent oxygen which is used to disinfect.

The excess acid is neutralized by adding base which produces salt and water and thus decrease the acidity.

Adding more acid would increase the acidity further.
Number one is the correct answer