The floor of a building consists of 3000 tiles which are rhombus-shaped and each of its diagonals are 45 cm and 30 cm in length. Find the total cost of polishing the floor, if the cost per m² is ₹ 4.
a) ₹ 4,000
b) ₹ 4,400
c) ₹ 4,800
d) ₹ 5,200