To evaluate the statements regarding the equation for gravitational potential energy \( PE = mgh \):
A) Mass does not matter: This statement is not true. The mass \( m \) is a crucial component of the equation, as it directly affects the amount of potential energy.
B) Height does not matter: This statement is also not true. The height \( h \) is essential to determining potential energy; it represents how high the object is above a reference point.
C) Potential energy is measured in newtons (N): This statement is not true as well. Potential energy is measured in joules (J), not newtons. Joules can be expressed as \( \text{N} \cdot \text{m} \) (newton-meters), but potential energy itself is not expressed in newtons.
D) All of the above are true statements when calculating PE: This statement is not true because all the previous statements are false.
Since multiple statements above are false, the one that aligns best with being "not true" for calculating potential energy is A) mass does not matter. Therefore, the best answer to select here, regarding which statement is not true, is A.