a.
My favorite pizza combinations are: sausage, peppers, and onions, mushrooms, extra cheese, and anchovies, and hamburger, sun-dried tomatoes, pepperoni, and sliced red potatoes.
b.
My favorite pizza combinations are sausage, peppers, and onions; mushrooms, extra cheese, and anchovies; and hamburger, sun-dried tomatoes, pepperoni, and sliced red potatoes.