Instructions: In this task, you are given a multiple-choice question and you have to pick the correct option. Answer with option indexes (i.e., "A", "B", "C", and "D").
Input: As the use of alt fuels increases, the use of what will decrease? (A) reusable fuels used for heating (B) fuels of the non reuse type power (C) fish swimming upstream in river (D) more hydro-electric power altogether
Output:
B