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.

Use of nuclear fuel would most likely reduce human contributions to which environmental problem?  
 (A) ozone thinning (B) landfill creation (C) shoreline erosion (D) greenhouse heating
D

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

Scientists have developed an allergy medication from a plant that is part of the rainforest food chain. What concern might develop when producing this medication from the plant?  
 (A) overproduction of the medication (B) increase in allergies in rainforest wildlife (C) lack of patients to test the new medication (D) decrease in a food source to rainforest wildlife

D