Final answer:
The anterior-posterior axis is associated with the frontal plane, which divides the body into anterior and posterior portions.
Step-by-step explanation:
The anterior-posterior axis correlates with the plane that divides the body into anterior (front) and posterior (rear) portions. This plane is known as the frontal plane, also sometimes referred to as the coronal plane. To clarify, the sagittal plane divides the body into right and left sides, the transverse plane divides it into upper and lower portions, and the oblique plane is used when a transverse cut is at an angle. Therefore, the correct answer to your question is (a) Frontal.