Laura is planning to buy four 5-lb bags of sugar, five 5-lb bags of flour, four 1-gal cartons of milk, and five 1-dozen cartons of large eggs. The prices of these items in three neighborhood supermarkets are as follows. A = Flour Supermarket I (5-lb bag) $3.79 $2.89 Supermarket II Supermarket III $2.98 (a) Write a 3 x 4 matrix A to represent the prices (in dollars) of the items in the three supermarkets. B = C = Sugar (5-lb bag) $3.15 $2.99 $3.74 ↓t (b) Write a 4 x 1 matrix B to represent the quantities of sugar, flour, milk, and eggs that Laura plans to purchase in the three supermarkets. → ↓ 1 Milk (1-gal carton) $2.99 $2.79 $2.89 Eggs (1-dozen carton) $3.49 $3.29 $2.99 (c) Use matrix multiplication to find a matrix C that represents Laura's total outlay (in dollars) at each supermarket.