Final answer:
The notion that intermediaries are most often used only in core services rather than supplementary services is incorrect, as they can be utilized in both areas in various industries, including financial and non-financial sectors.
Step-by-step explanation:
The statement that intermediaries are most often used in core service and not in supplementary services is false. Intermediaries can operate in both core and supplementary services. In the context of financial markets, banks act as financial intermediaries, creating a separation between savers who deposit funds and borrowers who take out loans. With financial intermediation, the individual savers and borrowers typically do not meet, and the deposited funds collect in a single pool which is then lent out by the institution.
Additionally, in economic activities involving goods and services outside of finance, intermediaries can also be involved in providing supplementary services to support the primary offerings of businesses, such as logistics and customer service support.