Answer:
A. The use of only the most productive breeds improves genetic diversity.
Humans experience two growth spurts. The first one occurs in early childhood at around the ages of 2 to 3, during which a child grows at a rate of 4 inches<span> per year on average. The other growth spurt happens during puberty. Girls grow about </span>3<span> to </span>3<span> ½ inches per year, and boys grow about </span>4 inches<span> per year during puberty.</span>
