Definition: You are given a question on high school chemistry. You are also given 4 answer options (associated with "A", "B", "C", "D"), out of which only one is correct. You need to answer the question by selecting the correct option. You should only answer with the choice letter, not the whole answer.
Input: When an ideal gas is allowed to expand isothermally, which one of the following is true?
(A)q = 0 (B)w = 0 (C)E = 0 (D)q = -w

D