Answer:
A, add value that exceeds the cost of their services.
Explanation:
Marketing intermediaries are individuals or firms that help with the the flow of goods and services from producer to end-user. These individuals or firms include wholesalers, retailers, marketing agents, etc.
Marketing intermediaries are help to increase the range of a product's or services' reach. Without these marketing intermediaries, the reach of products and services would not be wide enough.
Marketing intermediaries when assisting the flow of products and services bring skills such as specialization, marketing knowledge, capacity to segment the market to enable maximum reach, etc.
Cheers