Why does it take only a few homeotic genes to control the development of a eukaryote?

Why does it take only a few homeotic genes to control the development of a eukaryote? (1 point)

a. because each homeotic gene begins a cascade of events that leads to the formation of a specific body part
b. because eukaryotes have surprisingly small numbers of genes in any one cell
c. because each cell receives only a fraction of the total number of genes in the organism