The overriding problem with both theories of muscle growth, hypertrophy and hyperplasia, is that
a.
neither can be accepted as correct because muscles growth is difficult to study in humans
b.
neither one is theoretically possible
c.
neither has been studied by reputable scientists
d.
neither has been accepted by member of the fitness community

The answer is "A.  neither can be accepted as correct because muscles growth is difficult to study in humans".

Muscle growth happens on account of hypertrophy or hyperplasia.  

Hypertrophy is an expansion in the measure of the muscle because of an increment in the extent of the muscle strands, while hyperplasia is an increment in the quantity of muscle filaments.  

Hypertrophy comes in two structures, sarcomere hypertrophy, an expansion in the span of the contractile part of the muscle; and sarcoplasmic hypertrophy, an increment in the non-contractile bit of the muscle.  

Hyperplasia is the part of muscle filaments, coming about inevitably in a more prominent number of strands indistinguishable size from the firsts. It has been said that the quantity of muscle cells one is conceived with is all they will ever have, and the part isn't new filaments yet harm to existing strands.

a1 = unhealthy

a2= healthy

a3= healthy

true. these things define the personality of the person.