In these tissue cells, Lacunae are enclosed

The correct option is both (a) and (b) (which corresponds to both Cartilage and Bone tissue).

To understand why lacunae are found in both cartilage and bone tissue, let us break down the structure of these connective tissues step-by-step:
1. Definition of Lacunae: In histology, a lacuna (plural: lacunae) is a small space, cavity, or depression within the extracellular matrix of a connective tissue that contains an osteocyte (in bone) or a chondrocyte (in cartilage).
2. Presence in Cartilage: Cartilage is a specialized, semi-rigid connective tissue. The cells of cartilage, known as chondrocytes, are housed within small fluid-filled cavities called lacunae. These lacunae are scattered throughout the dense, gel-like extracellular matrix of cartilage.
3. Presence in Bone Tissue: Bone (osseous tissue) is a rigid, mineralized connective tissue. The mature bone cells, known as osteocytes, reside inside lacunae located between the concentric rings of the bone matrix (lamellae). These lacunae are connected to one another by tiny canals called canaliculi.
4. Comparison with Muscular Tissue: Muscular tissue consists of elongated muscle fibers (cells) specialized for contraction and does not contain a mineralized or chondrified extracellular matrix containing lacunae.

Therefore, since lacunae are characteristic structural features enclosing cells in both cartilage and bone tissues, the correct choice is both (a) and (b).