The is/are lymphatic tissue seen in the histological section of the ileum.

The Peyer's patch is/are lymphatic tissue seen in the histological section of the ileum.

Explanation:

Peyer's patch are clumps of lymphatic tissue that internally cover the mucosa of the small intestine, particularly the ileum, playing a very important role in the immune system, since they are sites of aggregation of large numbers of lymphocytes (which have the ability to recognize antigens and are responsible for triggering specific immune responses) and other accessory cells.

The correct answer is: Peyer's patches.

Explanation:

Peyer's patches are masses small in size of lymphatic tissue that are located in the ileum, the last part of the small intestine.  

Like all lymphatic tissue, Peyer's patches play an important role in the immune system; their location being strategic to monitor intestinal bacteria and preventing pathogens from invading this area.

Peyer's patches can be classified as lymphatic nodes, which means they are non-encapsulated lymphatic tissue.

i think its both a and b