Final answer:
Outsourcing can lead to a major disadvantage by having less control over quality and a reduction in expertise within the company, making both options A and B correct.
Step-by-step explanation:
Which of the following is a major disadvantage of product/service outsourcing? When businesses outsource, they might face several challenges. However, the offered options point to two primary disadvantages. firstly, having less control over quality, because when a company outsources, it may not have the same level of oversight and control over the manufacturing process or service delivery as it would in-house. secondly a reduction in expertise as outsourcing can sometimes mean that the company loses the opportunity to build its own internal skills and knowledge base in certain areas.
Therefore, the correct answer is 'd. Both A and B are correct'. Outsourcing can lead to both a reduction in the control over the quality of the product or service and a decrease in the accumulation of in-house expertise within a company.