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 Q]: What type of galaxy is the Milky Way?  
 (A) spiral (B) elliptical (C) irregular (D) oval
[EX A]: A

[EX Q]: In which case does a physical change occur?  
 (A) Ice melts into water. (B) Bread burns in a toaster. (C) A cake bakes in an oven. (D) Two chemicals form a new substance.
[EX A]: A

[EX Q]: Which characteristic does a euglena share with an amoeba?  
 (A) They reproduce by mitosis. (B) They eat by phagocytosis. (C) They respond to light stimuli. (D) They move by changing shape.
[EX A]:
A