Can I specify the type of entity for an OFAC check (person vs. business)?‍

Yes. By default, OFAC searches across all four categories: person, business/organization, vessel, and aircraft. You may optionally specify a search type if you want to narrow results (for example, only "person" or only "business"). In most cases, it is best not to send a type so the system checks all categories. If you do specify, the result will only match against that category.