Final answer:
In a posterior pelvic tilt, the hips and spine exhibit decreased lumbar lordosis, spinal flexion, and hip extension.
Step-by-step explanation:
During a posterior pelvic tilt, the position of the hips and spine is characterized by a decrease in lumbar lordosis, leading to a flattening of the lower back. In this position, the spine experiences flexion rather than extension. The hips are also in a state of extension. Hence, the correct answer to the position of the hips and spine during a posterior pelvic tilt is option 4) Decreased lumbar lordosis, spinal flexion, and hip extension.