Help please... question is in the picture

What graph correctly matches the equation y equals two negative x

Arestaurant offers a $12 dinner special that has 5 choices for an appetizer, 12 choices for an entrée, and 4 choices for a dessert. how many different meals are available when you select an appetizer, an entrée, and a dessert? a meal can be chosen in nothing ways. (type a whole number.)

Explain how you can use the associative property to evaluate (7x50)x4.