You are given a science question (easy-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:
Some pea plants always have peas with smooth skin. Other pea plants always have peas with wrinkled skin. How can a student best predict which kind of pea will grow from a seed that is planted?  
 (A) by checking the amount of water in the soil (B) by checking how often the pea plant receives sunlight (C) by checking how much space the plant will have to grow (D) by checking the type of peas growing on the parent plants

Ex Output:
D


Ex Input:
Some scientists have suggested that the Moon was formed when a large body struck Earth and broke off a piece of Earth billions of years ago. Which observation would best support this suggestion?  
 (A) The rocks of the Moon are older than Earth rocks. (B) The Earth has free standing water, but the Moon does not. (C) The Earth and the Moon are gravitationally locked together. (D) The chemical composition of Moon rocks is similar to Earth rocks.

Ex Output:
D


Ex Input:
A city is experiencing heavy smog formed by motor vehicle exhaust. Which of these weather conditions contributes most to the formation of smog?  
 (A) dry line (B) cold front (C) tropical cyclone (D) temperature inversion

Ex Output:

D