Which organization ensures quality control inspections within shipping companies?

The correct choice is the International Association of Classification Societies (IACS) because it is specifically responsible for establishing standards for the design, construction, and maintenance of ships and continues to oversee classification societies that carry out surveys and inspections on vessels to ensure they meet these standards. IACS plays a critical role in quality control, as its members adhere to a stringent framework that ensures ship safety and compliance with international regulations.

The other organizations mentioned serve different but essential roles within the maritime industry. The International Maritime Organization (IMO) develops global standards for the safety, security, and environmental performance of international shipping, but it does not conduct inspections itself. The American Bureau of Shipping (ABS) is one of the classification societies that IACS recognizes, meaning it aligns with IACS standards, but it operates at a more localized level. The International Safety Management (ISM) code establishes a framework for the safe management and operation of ships, but it does not focus directly on quality control inspections within shipping companies. These distinctions clarify why IACS is the most relevant organization for the quality control described in the question.