Final answer:
The correct guideline for good posture while standing is to maintain a straight spine, which aligns the body's center of gravity above the pivot point in the hips and prevents back strain.
Step-by-step explanation:
Among the guidelines for good posture while standing, the correct option is to maintain a straight spine. Good posture involves aligning the body so that the center of gravity is directly above the pivot point in the hips, which helps to minimize back strain and potential damage to disks. When standing, it is important to distribute your weight evenly on both feet, keep your shoulders relaxed but not rounded, and avoid locking your knees to maintain good posture.
One of the guidelines for good posture while standing is to maintain a straight spine. This means that you should avoid slouching or rounding your shoulders. Additionally, it is important to avoid locking your knees while standing, as this can put strain on your back and affect your overall posture.