The coefficients of the quadratic expression \(3x^2 + 5x - 12\) are the numerical factors in front of each term.
- The coefficient of \(x^2\) is 3.
- The coefficient of \(x\) is 5.
- The constant term (which is \(x^0\)) is -12.
Therefore, the correct list of coefficients for the quadratic expression is:
C) 3, 5, -12.