You will be given a definition of a task first, then some input of the task.
Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.

Problem: an art gallery has only paintings and sculptures. currently, 1 / 3 of the pieces of art are displayed, and 1 / 6 of the pieces on display are sculptures. if 1 / 3 of the pieces not on display are paintings, and 800 sculptures are not on display, how many pieces of art does the gallery have ?
Options: a. 360, b. 1800, c. 540, d. 640, e. 720
Output:
b