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". 

[EX Q]: The man takes a shot at the gift wrapping. The lady finishes wrapping the gift. The man folds an edge, and the lady tapes it. the man <sep> (A) opens the package and allows the lady to remove a box lid. (B) closes and rewraps the gift. (C) squeezes her hand, and she takes a picture. (D) presents the box to the camera and talks.
[EX A]: D

[EX Q]: [header] How to polish rocks [title] Choose the right rock. [step] You can polish any stone you wish, but there are certain characteristics of a stone that will make it easier to polish. If you want an easy stone to polish, pick a somewhat softer stone like onyx, limestone or calcite. <sep> (A) [substeps] You can polish diamond, granite or ceramic stones by cutting thin pipe holes or inserting dry mortar into one side of each hole. Look for a stone that resembles a diamond, but not necessarily a diamond. (B) Otherwise, a smoother, more pumice-like stone will be more difficult to polish. [substeps] Emeralds and equilateral manganese are both excellent mineral polishes. (C) Stones that are very hard will take a much longer time to polish. However, though hard rocks take a long time to sand, they yield more shine than softer rocks. (D) Softer rocks will actually work more well, and might look better to polish very old stones, but brighter stones tend to chip quicker. [substeps] Rubies, sapphires, and emerald are good options.
[EX A]: C

[EX Q]: [header] How to choose a natural sunscreen [title] Look for 10 percent zinc oxide or titanium dioxide. [step] Natural sunscreens often use ingredients that physically, rather than chemically, block the sun. Because these don't offer a high spf on their own, you need to make sure they have a high enough concentration in the sunscreen to actually block the sun's uv rays. <sep> (A) Leave the sunscreen on your face at all times, or take it off when you're using sunscreen or take a shower. [substeps] Even sunscreen that is produced with zinc oxide will leave you with zinc oxide in your skin. (B) Zinc oxide is a plastic sunlight absorbing agent. It will compensate for your copper and titanium electrolyte needs by protecting you from uv light, as well as using their uv wavelengths. (C) Choose a sunscreen that has a 10 percent or higher concentration of zinc oxide or titanium dioxide. [substeps] These two ingredients are the only fda-approved ingredients for blocking the sun that are often used in natural sunscreens. (D) [substeps] The middle part of a sun protected product may also be the sun itself. Zinc oxide can also be found in petroleum products, including margarine or olive oil.
[EX A]:
C