Using a spreadsheet program, you choose to analyze the daily temperature changes using an XY scattergram, connect the points with a curve. Your temperature probe is accurate to within +/- 0.1C, so you add error bars that go up and down -.1C:

Ithink that b is correct but just in case wait to see if someone else answers

By water evaporation from the leaves is created a negative pressure at the top of the tree that promotes the ascension  of the water through channels that are called xylem. there are also two molecule forces that are involved: the intra-water molecules cohesion (water molecules stick to each other) and the adhesion when the water molecules stick to the channels they are running in. this is what enables water to go from the roots to the top of a tall tree.