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 have healthy kidneys [title] Stay hydrated. [step] Staying properly hydrated is one of the best ways to keep your kidneys healthy. Without adequate water, your kidneys can lose some of their ability to filter your blood, and may even become damaged over the course of your lifetime. <sep> (A) [substeps] Drinking water helps your kidneys flush sodium, urea, toxins, and waste out of your body. By staying properly hydrated, you can significantly reduce your risk of developing chronic kidney disease. (B) Aim to drink at least 8 fluid ounces of water every day. This will help reduce any additional fluid or waste in your system and will also allow you to more easily relieve the symptoms of kidney problems. (C) Insufficient water will contribute to poor kidney function, such as kidney failure and rheumatoid arthritis. Trying to drink water with no filter might cause further kidney damage. (D) [substeps] The best amount of water recommended by experts is 1 gallon a day (2.5 liters) each. Drink bottled water, but you don't need soda, fruit juices, or other non-carbonated beverages; opt for bottled water.
answer:
A


question:
[header] How to make a composite longbow [title] Select your wood. [step] Go to a hardware store or an archery store. Only cut live trees if you are sure it is a suitable wood, and are prepared to properly dry the wood. <sep> (A) [substeps] Non-live trees can be prepared for a shoot near a slope. However, live trees that have been broadcast on the news should be cut or damaged, to avoid soiling the tree. (B) Just-cut, wet wood won't work well. [substeps] Look for a board that's 6 feet (1.8 m) long , 1 " x2 ". (C) [title] Squeeze out the sap from each antler. [step] Squeeze each antler gently to release the excess sap in the old antler. (D) For smaller shoots, use white cedar or fir bark. If the shoot is large, use pine bark or maple bark.
answer:
B


question:
[header] How to poach an egg using a microwave [title] Get a microwave safe mug and lid. [step] Most plastic, glass, or ceramic mugs and lids will say " microwave safe " on the bottom. Use a mug and lid that specifically says microwave safe. <sep> (A) It's acceptable for very big eggs to be too small to cook in the microwave. [title] Heat up the microwave for about 30 seconds. (B) [substeps] Pan-bottom mugs will not be the best cup. The rings on top are more likely to leak than the ones on top. (C) Avoid giving the mug a lid, since you will heat the egg without the lid. [title] Heat the egg in a microwave safe skillet with the lid on. (D) Do not use metal materials or foil in the microwave. [title] Fill the microwave safe mug with ½ cup of water.
answer:

D