The central part of the proximal region of the centriole is proteinaceous and called the A , which is connected with tubules of the peripheral triplets by B made of protein.

Step-by-step solution

The central part of the proximal region of the centriole is proteinaceous and called the hub, which is connected with tubules of the peripheral triplets by radial spokes made of protein. The centrioles form the basal body of cilia or flagella, and spindle fibres that give rise to the spindle apparatus during cell division in animal cells.