Can you please show me how they got this answer?

Palmer Frosted Flakes Company offers its customers a pottery cereal bowl if they send in 3 boxtops from Palmer Frosted Flakes boxes and $1. The company estimates that 60% of the boxtops will be redeemed. In 2014, the company sold 675,000 boxes of Frosted Flakes and customers redeemed 330,000 boxtops receiving 110,000 bowls. If the bowls cost Palmer Company $3 each, how much liability for outstanding premiums should be recorded at the end of 2014?

a.$270,000

b.$50,000

c.$75,000

d.$138,000