The length of a small rectangular garden is four more feet than twice its width, w. The area of the garden must be 30 square feet. What equation represents the area of the garden and what is the length of the garden in feet?

A. A=w(2w+4); length = 8 feet
B. A=30w; length = 4 feet
C. A=w²+4; length = 5 feet
D. A=2w(w+4); length = 10 feet