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.

Jolie wanted to eat a hard-boiled egg for breakfast. She put the egg in boiling water for fifteen minutes. When she broke the shell, the liquid parts of the egg had become solid. This was because  
 (A) heating removed the water from the egg. (B) heating changed the chemical bonds in the egg. (C) boiling brought the solid egg parts to the surface. (D) the bacteria living in the liquid egg were killed.
B

Which land feature is most likely the result of a glacier?  
 (A) large, arid desert (B) deep, bowl-shaped lake (C) long crack in the ground (D) volcanic mountain range
B

Leucine is one of the amino acids your body needs but cannot make. Which of these happens so that the human body can obtain leucine?  
 (A) The body converts other amino acids to leucine. (B) The body stores carbohydrates containing leucine. (C) The body breaks down fatty acids to obtain leucine. (D) The body digests protein in food to obtain leucine.

D

