The first one seems the most correct
Hai! I can't really see it clearly but A would match with R.
is there any way u could retake the picturee?
Not 100% sure here but from what I remember I think it is called osmosis... It is if the water is leaving or entering the cell.
The half-life of a radioisotope is the amon the symbol 42He, the subscript 2 is the mass number for helium and the superscript 4 is the atomic number for helium.