National company has two support departments A&B and two operating departments X&Y. for the first quarter 2021, Budgeted overhead costs before any interdepartmental costs allocations were: A $800,000, B $1,500,000, X $5,000,000 and Y $11,000,000. Support work supplied by A to B 20%, to X 50% and to Y 30%. Support work supplied by B to A 25%, to X 35% and to Y 40%. Using step-down method and allocating department A cost first, out of its cost, the amount allocated to department B is:

a. $800,000

b. $240,000

c. $160,000

d. $400,000