In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D". 
One example is below.
Q: [header] How to create a christmas tree forest [title] Consider the type of tree you want to plant. [step] There are a wide variety of christmas trees and include fir, pine, spruce, cypress, and cedar. These trees thrive in different climates and look different from one another. <sep> (A) It is important to research the tree before setting up your tree to try it out to make sure you can write the tree's growing season so that you can get the most supplies you need. If you're just interested in having a tree stand out, then make sure to check for the following : [substeps] Spruce trees. (B) [substeps] Trees green may be used in a mix of green and evergreen. Greens, such as pintos and olive oil, may be more delicate than these. (C) Where the trees grow together is up to you. [substeps] Spruce trees light up the night for hours in the morning and drown out the morning sunrise between afternoons. (D) Think about where your tree forest will be located and choose a tree that can thrive in that climate. [substeps] Balsam firs are a popular christmas tree species that grow in the northern united states and canada, in hardiness zones 3-5 or states like minnesota, north dakota, and montana.
A: D
Rationale: This is a good example. Only option D is about Christmas trees. So, it's the correct option.
Q: [header] How to touch the bottom of a pool [title] Go to a local or private pool that has a diving board that you are allowed to use. [title] Set the diving board to a loose setting, for some boards are set stiff. [step] You might need some help doing this, but only do it if you are not breaking any rules. <sep> (A) However, if you are at the pool and have a slide to choose from you can always set this up yourself. [title] Find a heat and a place that has a completely smooth surface to go. (B) [title] Make sure you put your board in warm water, not on dry skin before diving. [step] A cool place to dive is near the water's edge, but pools tend to be drier and have more moisture, which can lead to dry skin. (C) [title] Climb up the steps on the board. [title] Walk quickly to the point where the tip of your big toe is about 3-4 inches (7.6-10.2 cm) away from the edge of the diving board. (D) [title] Position the diving board up at the water's edge. [step] This is especially true if you are swimming with friends, as most pools let you board with anybody who you trust.
A:
C