Answer:
a. user; original equipment manufacturer(OEM)
Step-by-step explanation:
Business markets refer to purchase and sale of products by businesses with one another. For example, output for one business might be used as an input for another.
A business would be termed as a user when it purchases goods from another business, wherein such goods are not directly used in the manufacturing or creation of it's products.
Original Equipment manufacturer refers to a business which buys certain products and subsequently incorporates them in an altogether newer product within it's brand name.