Dynamic stretches are part of an effective warm-up because they can

lubricate muscles in the activity

decrease cardiovascular difficulty in the activity

expand lung capacity in the lung activity

build endurance for the activity

Option A, Lubricate muscles in the activity

Explanation:

Muscles become flexible during dynamic exercise. During such exercises the temperature of body increases which enhances  the flow of blood through the muscles and hence provide oxygen and glucose to muscles. Dynamic exercise provides the large amount of energy which is required by muscles in the start of any exercise/activity.  This also activates the muscles and increases the range of motion.

Hence, option A is correct

as resources become scarce because of population growth, the growth decreases after few years due to lack of resources and food.

answer; i believe the correct answer is (sporophyte);