The multiple nuclei in skeletal muscle cells are the result of the

Fusion of embryonic myoblasts, each having its own nucleus to many other myoblasts to form the multinucleated skeletal muscle fibers.

Explanation:

The multiple nuclei in skeletal muscle cells are as a result of fusion of embryonic myoblasts, each having its own nucleus to many other myoblasts to form the multinucleated skeletal muscle fibers. This gives rise to multiple copies of genes, allowing production of the large amounts of proteins and enzymes and ATPs needed for muscle contraction.