At the market, Joey buys 3 avocados for $0.40 each and 5 lemons for $0.40 each. The cashier in training rings up 3 × 0.40 and then 5 × 0.40 to get the total. The experienced cashier says to add the 3 plus 5 in his head and then ring up 8 × 0.40. What property says that these two totals would be the same?

multiplicative identity
associative property of multiplication
distributive property
commutative property of multiplication