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.

A bright object with a long tail of glowing gases is in orbit around the Sun. This object is most likely  
 (A) a planet (B) a star (C) an asteroid (D) a comet
D

A student hypothesizes that algae are producers. Which question will best help the student determine if this is correct?  
 (A) Do algae consume other organisms? (B) Which organisms consume algae? (C) Do algae use sunlight to make food? (D) Could an ecosystem survive without algae?
C

Ocean currents, prevailing wind patterns, and other atmospheric disturbances are initially caused by which of these?  
 (A) differences in the cycles of the Moon (B) gravitational pull of the Sun (C) incoming solar radiation (D) ozone layer depletion

C