Which of the following is a linear equation in the form ax + b = c (with a ≠ 0) and correctly identifies a, b, and c?

• A. 3(x + y) = 6, which expands to 3x + 3y = 6
• B. x² + 3 = 5, where a = 1, b = 3, c = 5
• C. 0x + 4 = 4, with a = 0, b = 4, c = 4
• D. 2x + 7 = 15, with a = 2, b = 7, c = 15

Answer: (D)