What is dense in nature, provides strength and protection, and acts as the attachment for skeletal muscles?

The correct choice is the cortical plate, which is dense in nature and plays a significant role in providing strength and protection to the bones of the skeleton. It is composed of compact bone, which is the hard, outer layer of bone that gives it structural integrity. The cortical plate is essential for load-bearing along with protecting the internal structures of bones and serving as the attachment point for skeletal muscles.

It is important to understand that while compact bone is indeed dense and contributes significantly to the strength of bones, the term "cortical plate" specifically refers to the outer layer of compact bone that lines the surface of the bone, which clarifies its role in attachment and protection. Cancellous bone, on the other hand, is less dense and consists of a network of trabecular (spongy) bone that is more involved in metabolic processes rather than structural support. Cartilage, while it provides cushioning and allows for movement at joint surfaces, does not serve as an attachment point for muscles like the cortical plate does.