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.
--------
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

Answer: C

Question: Which best describes sexual reproduction in all animals?
(A) Egg and sperm join together. (B) Pollen and seed join together. (C) Offspring have traits of only one parent. (D) Offspring are identical to one parent.

Answer: A

Question: Gulf sturgeons, a type of fish, live in saltwater along the gulf coast of Florida. They swim upriver to breed in clean freshwater. After several years, the young sturgeons migrate downriver to the coastal saltwater environments. Which would be the most likely effect on gulf sturgeons if dams were built along these rivers?
(A) Gulf sturgeons will change over time into a new species. (B) Gulf sturgeons will move from coastal rivers into the ocean. (C) The gulf sturgeon population will decline due to loss of habitat. (D) The gulf sturgeon population will adapt to breeding in saltwater.

Answer:
C