Diego is building a kitchen table and a coffee table. The legs of a kitchen table must be twice the height of a coffee table and there are 4 legs on each table. He writes the expression 4(2x) + 4(x) to model his building plans. What does the coefficient of 4 represent?

A. 4 represents the height of one kitchen table leg.
B. 4 represents the number of legs on each table.
C. 4 represents the height of one coffee table leg.
D. 4 represents the total number of table legs.