Blue Brothers' cleaning products and equipment are sold to consumers and commercial cleaning companies in Clean Supply's janitorial supply and equipment store. Blue Brothers' relies heavily on Clean Supply to help sell its goods and services to customers. Clean Supply is a$($n$)\_\_\_\_\_\_\_\_$ of Blue Brothers' products.

a$.$

Distributor

b$.$

Competitor

c$.$

Joint ally

d$.$

Customer

e$.$

Strategic ally

f$.$

Subsidiary