Which type of firm is one of the three major categories of firms that conduct marketing research? a. Marketing research companies b. Advertising agencies Companies that produce or sell products and servicesc. All of these are correct. d. None of these are correct.

c. All of these are correct

Explanation:

Marketing research refers to assembling, analyzing and processing information, which is used to determine and create the marketing strategies a firm shall follow.

Marketing research refers to analyzing such data which helps a business to create define applicable marketing strategies in a given scenario.

A firm may carry out it's own marketing research or outsource the same function to marketing research companies or advertising agencies.

Hence all three, Marketing research companies, Advertising agencies and companies that produce or sell goods may conduct marketing research.

the answer is i don't know

i would say their habit of breaking down.