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]: [header] How to paint masonry walls [title] Remove any flaked or peeling paint from the masonry. [step] If the wall has already been painted, you need to remove any old paint that is loose, peeling, or flaking away. On an exterior wall, this is most efficiently done with a sandblaster. <sep> (A) New paint must be removed from the wall first, gently scraping around the edges with a rat-tail tail reciprocating scraper. This is most often done on exterior paint walls that are still meant to protect it from debris. (B) In areas where a sandblaster would be too messy and cumbersome, loose paint can be removed with a stiff wire brush and a paint scraper. [substeps] Failing to remove loose and peeling paint can result in the paint flakes mixing in with your fresh coat of paint and marring the finish. (C) [substeps] Make sure to turn off the water. Do not flush the wall down the drain. (D) If there is a paint-resistant paint strip still clinging to the wall, it may be painted to the wall as well, but not directly under it. [substeps] Using a sandblaster may be wise, but if the paint is not taking off, it may be better to start by sanding lightly.
[EX A]: B

[EX Q]: [header] How to clean rubber boots [title] Wipe away light dirt and grime. [step] If your boots aren't especially dirty, you can usually clean them easily with a damp cloth. To prevent dirtiness from building up on your boots and causing longer cleaning times, do this after each time you use your boots. <sep> (A) Before handling an object or stepping on something wet, make sure you wipe it away on a rag first. Use a mild soap and water to wipe off even the smallest traces of dirt. (B) [substeps] To increase the dirt fighting potential of your damp cloth, mix 1 tsp (5 ml) of dish soap with a ¼ gallon (1 l) of water. Douse your rag in this, and wipe down the boots. (C) [title] Grind three pounds (177 g) of dry powder on a coffee grinder. [step] The dry powder will help to transfer dirt and dust to the boots. (D) This will clear little dirt and grime off of your boots, leaving them looking brand new. [substeps] If your boots are already cleaned, you may need to consult a shoe store or partner to inspect them for a better cleaner.
[EX A]: B

[EX Q]: [header] How to avoid social networking scams [title] Regulate your privacy settings. [step] Most social networks, such as facebook, twitter, and instagram, allow you to control who sees your information, photos and posts. To help stay safe, try to limit the amount of people who can see your information to as few as necessary. <sep> (A) [substeps] Think about who will be seeing the information you post. If your privacy settings are not controlled, you will be giving information about yourself out to anyone with access to the internet. (B) If your privacy settings are not relaxed, the last thing you want is for your friends and family to find out. [substeps] You can even block friends and talk in private without your friends knowing. (C) This is a good strategy if you are trying to avoid someone else. [substeps] Set your security settings to " what ever " so people cannot see your content. (D) [title] Plant an anti-hackers alert in your group or organization. [step] You can actually prevent users from the site from looking at your personal information.
[EX A]:
A