Final answer:
Option A, REP's who are selling or buying their own property, is most likely excluded from REIX policy coverage as E&O insurance typically covers professional services provided to clients, not personal transactions.
Step-by-step explanation:
The transaction excluded from coverage under the Real Estate Errors and Omissions Insurance Exchange (REIX) policy is most likely option A: REP's who are selling or buying their own property. Generally, E&O policies are intended to provide coverage for errors and omissions that occur in the course of professional services provided to clients, and not for personal transactions.
If a Real Estate Professional (REP) is dealing with their own property, it is not a client-based service, and hence, typically not covered under an E&O policy. Additionally, developers selling or buying their own properties can also be excluded, but this would depend on the specific terms of the policy under 'developers' exclusions'. It is essential to review the specific terms and conditions of the policy to understand the exact coverage and exclusions.