Detailed Instructions: You are given a mathematical question described with an open-ended vocabulary. Questions in this task involve real-world situations, describing a mathematical problem. You are also given 4 or 5 answer options (associated with "A", "B", "C", "D", "E"). Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D', 'E'. LaTeX mathematical format (the standard way to express mathematical expressions in the typesetting software known as LaTeX) is used to express equations. Each question is solvable with high school math knowledge. Give only one answer for each question.
Problem:The populations of two species of bacteria in a petri dish vary inversely. If there are 1,000 bacteria of species A when there are 500 bacteria of species B, how many bacteria of species B are there when there are 2,000 bacteria of species A ?
(A)250 (B)500 (C)750 (D)1,000 (E)2,000
Solution:
A