Final answer:
Swimming enhances range of motion during pregnancy and postpartum by providing buoyancy that reduces stress on joints.
Step-by-step explanation:
The activity that enhances range of motion during pregnancy and postpartum is swimming. Exercising in water provides buoyancy that places less stress on joints, making it a suitable exercise for pregnant women and new mothers. Swimming involves a wide range of motions and stretches multiple muscle groups, helping to improve flexibility and maintain overall health.