For the given transportation problem:

	To
From	A	B	C	Supply
X	$10	$19	$12	100
Y	$17	$13	$9	150
Z	$20	$18	$14	505
Demand	80	120	70

a) Based on the given demand and supply, the given transportation problem is [ Select ] ["unbalanced", "balanced", "", ""]

b) Before finding the initial solution, a [ Select ] ["dummy node", "dummy destination node", "dummy supply node", "both dummy dest. and supply node"] should be introduced.

c) The total cost of the initial solution developed using the intuitive lowest-cost method will be [ Select ] ["3150", "3100", "3820", "3190"]

d) The total cost of the optimal solution = [ Select ] ["3150", "3045", "3000", "3190"]