Detailed Instructions: 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.
Q: Traveling in opposite directions, buses A and B are passing each other at the relative speed of 25 km/h, while a passenger on bus A walks toward the back of the bus at the speed of 5 km/h. What is the velocity of the passenger on bus A relative to bus B?
(A) 20 km/h in the direction of bus A (B) 20 km/h in the direction of bus B (C) 30 km/h in the direction of bus A (D) 30 km/h in the direction of bus B
A:
A