The question asks which structure is found in animal cells.

1. The question asks which structure is found in animal cells.
   • A. A cell wall is a rigid layer found outside the plasma membrane of plant cells, fungi, bacteria, and algae, but not animal cells.
   • B. A ribosome is a macromolecular machine found within all living cells, including animal cells, that performs protein synthesis.
   • C. A middle lamella is a pectin layer that cements the cell walls of adjacent plant cells together. It is not found in animal cells.
   • D. Pyrenoids are sub-cellular microcompartments found in the chloroplasts of algae and hornworts, involved in carbon fixation and starch synthesis. They are not found in animal cells.

The correct option is B.

• B. Ribosome