A licensed professional is hired at a consulting company to develop an emissions treatment method...

NPPE ethics emphasizes compliance with law, due diligence, and protecting the public and environment. Approaching a regulatory limit for a controlled pollutant is a foreseeable compliance and risk-management issue that must be addressed, not justified by improvements elsewhere. The best initial step is to inform the client promptly, document the concern, and collaborate on design or operational changes that reduce CO emissions with a comfortable margin below permitted limits (B). This aligns with professional obligations to provide competent advice, manage risk, and avoid creating a system that is vulnerable to exceedances due to variability, upsets, or measurement uncertainty. Option D is unacceptable because trading one regulated harm for another without ensuring compliance violates the duty to comply with environmental requirements. Option C is premature as an “initial” action; exemptions/variances are not a default solution and would not typically be sought before exploring feasible mitigation within the design. Option A is overly extreme and prescriptive; scaling back targets may be one option, but the initial professional response is to seek practical mitigation and ensure compliance rather than directing abandonment. Therefore, B is best.