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 bathe a pregnant guinea pig [title] Select a shampoo. [step] There are all types of shampoos for pets. For your guinea pig, make sure the shampoo is made specifically for small animals (it should say so on the bottle). <sep> (A) Otc shampoos and chemical shampoos are good choices. Avoid shampoo labeled specifically for guinea pigs and those formulated for females. (B) This way, both animals can use the shampoo and their fur will be clean. While many shampoos claim to free your guinea pig from " reye's syndrome ", this actually isn't true. (C) [substeps] Make sure that it is specially formulated for pregnancy-therefore not designed for your guinea pig. You can get shampoo from the veterinarian. (D) A small animal-specific shampoo will keep your guinea pig's skin from drying out or becoming irritated. Since your guinea pig is pregnant, the shampoo should also be non-medicated to prevent ingredients absorbing through her skin that could harm her unborn babies.
answer:
D


question:
[header] How to study the phenomenon of light as a nonequilbirum state of matter [title] Understand how thermodynamic systems are categorized. [step] Thermodynamic systems in nature are divided into two types. One is systems that are at equilibrium state with the environment and the other is systems that are in a state of nonequilibrium with the surroundings. <sep> (A) On earth, nature has a preference for systems that are at an equilibrium state with the surrounding. This is so due to the principle of minimum energy that every object in the universe aspires to have. (B) For example, gas rising in temperature throughout the day can be divided into microorganisms in the environment. [substeps] For example, gas rising in temperature in the atmosphere can be divided into molecules in the environment. (C) [substeps] Equilibrium is fundamental in thermodynamics. Other systems include stars, planets, and oceans. (D) [title] Learn about the term " rock hydrodynamics ". [step] Rock hydrodynamics refers to the transfer of water to the earth's surface.
answer:
A


question:
The boy falls of and gets back on the ball before he falls off again. He tries to sit on the ball but the ball rolls away. he <sep> (A) tries again to sit on the ball. (B) sits again and another boy tries to pull him back on the ball. (C) walks away and the bell rings for the homerun. (D) retrieves it and continues to sit on and fall off the ball.
answer:

D