Final answer:
The property of multiplication being demonstrated in the equation is the Distributive property.
Step-by-step explanation:
The property of multiplication being demonstrated in the given equation is the Distributive property. The distributive property states that when you multiply a number by a sum, you can also multiply each term inside the sum separately and then add the results. In this equation, the distributive property is being applied to the variable 'a' being multiplied by the sum of 'B' and 'C'.