Answer:
A). It is the most common and practical type of stretching
Step-by-step explanation:
PNF is Proprioceptive Neuromuscular Facilitation whose main aim is to increase range of performance and motion. It is most common type of exercising and stretching technique which is beneficial for muscle elasticity and on both active and passive motions of muscles.
Proprioceptive Neuromuscular Facilitation (PNF) is one of the most advanced form of muscle elasticity and flexibilty training, which includes the stretching of muscles and contracting of the muscle being targeted.
Hence it is the most common and practical type of stretching.