You are given a science question (hard-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

Ex Input:
One type of cold remedy is an effervescent tablet that breaks down in water. When the tablet is placed in water, it forms gas bubbles. In this example, the formation of a gas  
 (A) is a physical property. (B) occurs when adding water to acid. (C) is a sign of a chemical change. (D) occurs when the water boils.

Ex Output:
C


Ex Input:
What best explains why some cooking pans have rubber handles?  
 (A) The rubber in the handles is easy to hold. (B) The rubber in the handles is a good insulator. (C) The rubber in the handles keeps the food in the pan hot. (D) The rubber in the handles keeps the metal in the pan cool.

Ex Output:
B


Ex Input:
In pea plants, the trait for round seeds is dominant over the trait for wrinkled seeds. If a pure dominant plant with round seeds is crossed with a plant with wrinkled seeds, what can be predicted about the offspring plants?  
 (A) They will always produce round seeds. (B) They will only produce wrinkled seeds. (C) Each offspring plant will have some round and some wrinkled seeds. (D) Unless the plant with wrinkled seeds was pure recessive, no prediction can be made.

Ex Output:

A