instruction:
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".
question:
[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.
answer:
C

question:
A woman is shown leaning against a wall. Several ballerinas are shown in a room. different techniques <sep> (A) are demonstrated by them. (B) are shown for performance. (C) are shown for ballroom dancing. (D) are shown to teach the groups how to dance.
answer:
A

question:
[header] How to keep your computer secured [title] Go to start, hover over all programs, at the top, click on windows update and microsoft will check updates recommended for your computer. [title] Go to start, on the search text field, type in windows update and press enter. [step] Microsoft will look for the newest updates recommended for your computer. <sep> (A) [ + ] [title] Click more and reinstall the old windows update. [step] You may want to enable updates again, if recommended will be at the top of this article, make sure it is enabled. (B) [title] In the start menu, close' new case'. [title] Go to start' windows update'. (C) [title] Right-click on the location of the start menu button. [step] Click on control panel that is located on the list. (D) [title] Go back to start and click' trusted'. [title] Type in the name of any program you want to keep, and press enter on the keyboard.
answer:
C