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: Use the information below to answer the question. Manufacturing uses many steps to change natural resources into products. Some of these steps change natural resources into industrial materials. These steps are called primary processes. All of the following are primary processes except
(A) melting iron ore. (B) producing lumber. (C) molding plastic. (D) crushing rock into gravel.
A:
C