Final answer:
Frank Douglas should acknowledge Carl Sheen's contribution to the research report, according to CFA Institute Standards of Professional Conduct; failure to do so, despite any disagreement on conclusions, constitutes a violation.
Step-by-step explanation:
The question pertains to the CFA Institute Standards of Professional Conduct, specifically regarding the appropriate recognition of professional contributions in the research process.
According to Standard V(A) - Diligence and Reasonable Basis and Standard II(C) - Professionalism, if Frank Douglas included Carl Sheen's analysis and research in the final report, he is required to acknowledge Sheen's contribution regardless of whether or not Sheen agreed with Douglas's final recommendations.
The CFA Institute's standards mandate that members and candidates must fairly represent the contributions of others, thus, omitting Sheen's name when his work was used constitutes a violation of the CFA Institute Standards of Professional Conduct.