Various connective tissues and different parts of a given bone have diverse anatomical features.
Compact bone (B) is also called cortical bone or dense bone. It has osteons packed around a haversian canal. The bony matrix is filled with ground substance and salts.
Cartilage (C) is a firm tissue but is more soft and flexible in comparison to bone. It has chondrocytes embedded in a fibrous tissue matrix.
Adipose tissue (D) is a loose connective tissue made of cells called adipocytes. The cells are laden with fat. This tissue also cushions and insulates the body.
Therefore, options B, C and D are incorrect.
Spongy bone (A) is a component of cancellous bone. It is not as strong as cortical bone. It is important for producing blood cells and is typically characterized by open spaces partially filled by an assemblage of needlelike structures.
Therefore, option (A) is correct.