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 Input:
[header] How to buy a wood burning stove [title] Consider your heating needs by evaluating the size of your home. [step] You will need to determine the heat load necessary to maintain the square footage of the area you want heated. Heat load is measured in btus, or british thermal units. <sep> (A) Inquire about btus and thermal units using online resources. [substeps] Btus heat packs can be found at home improvement stores, department stores, and some gas stations. (B) To determine how much heat you need, pay attention to the dimensions of each room you intend to fire in. [substeps] The larger the square footage, the larger your fire seats will need to be. (C) You will need 25 to 30 btus per square foot. [substeps] Measure each room to be heated with measuring tape. (D) Btus are rated from 2000-1000. Btus can be changed or altered depending on the size of your home.

Ex Output:
C


Ex Input:
We see a person sharpen a knife on a sanding disc. The person touches it and turns it off. The person turns it on and then off off. we <sep> (A) see the person sharpening the knife on a cookie sheet. (B) see a man run in slow motion. (C) then see the title screen. (D) see the man talking to the camera.

Ex Output:
D


Ex Input:
[header] How to add phenolic acids to your diet [title] Eat lots of fruit. [step] One of the richest sources of phenolic acid is fruit. Phenolic acid is present in different fruits such as pears, grapes, and berries. <sep> (A) Fruits that contain plant-derived phenolic acid include oranges, apples, lemons, pineapple, strawberries, grapefruit, and apricots. [substeps] Foods with multiple levels of phenolic acid include blueberries, tomatoes, peaches, apples, raspberries, cucumbers, kiwi, and apples. (B) Strive to eat between 1.5 and 2 cherries and a banana per day. [title] Choose broccoli and other vegetables. (C) [substeps] To increase your production of phenolic acid, you should eat three strawberries, two blueberries, and one lime of grapefruit. Leafy green vegetables such as spinach and kale are also good sources of phenolic acid. (D) Adding a variety to your diet can ensure that you increase your daily phenolic acid intake. Products manufactured from these fruits, such as juice or wine, also contain phenolic acid.

Ex Output:

D