Calgary Corporation is closing one of its divisions. Operating data on this division follows:

Sales: $80,000

Variable Costs: $40,000

Overhead: $40,000

Overhead consists of $30,000 in salary and $10,000 for rent and insurance. The salary is for the chief engineer, who will continue to work for Calgary even if the division is closed. Rent and insurance that will cease if the division is closed is an:

a.) unavoidable and irrelevant cost

b.) unavoidable and relevant cost

c.) avoidable and irrelevant cost

d.) avoidable and relevant cost