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.

Tobias rode his bike on a road for a 2 hr period. On average, he passed a 1 km marker every 3 min during this period. Which of the following was his average speed for this 2 hr period?  
 (A) 10 km/hr (B) 15 km/hr (C) 20 km/hr (D) 25 km/hr
C

During which phase of meiosis does the separation of homologous chromosomes occur?  
 (A) prophase (B) anaphase (C) metaphase (D) telophase
B

Which two environmental changes usually cause certain animals to migrate?  
 (A) change of season and fewer predators (B) change of season and less food (C) loss of habitat and fewer predators (D) loss of habitat and more food

B