Peyer's patches and the tonsils are part of the collection of small lymphoid tissues that protect the upper respiratory and digestive tracts from infection and are referred to as

a) lymph nodes
b) malt or mucosa-associated lymphatic tissue
c) germinal centers
d) lymphatics

B) MALT or mucosa-associated lymphatic tissue

Explanation:

Lymphatic nodules are the secondary lymphatic tissues that lack any surrounding capsule and are present like egg-shaped tissue masses. The lymphatic nodules present in the lining of some organ systems such as gastrointestinal tract, urinary system, and the respiratory airways are called mucosa-associated lymphatic tissue (MALT) as these lymphatic tissues are present in their mucous membranes.

For example, Peyer patches and tonsils. Peyer's patches are the lymphatic nodules present in intestinal wall, and the appendix. Tonsils are the secondary lymphatic tissues present in a ring about pharynx.

the major parts of the digestive system:

salivary glands.

pharynx.

esophagus.

stomach.

small intestine.

large intestine.

rectum.

accessory digestive organs: liver, gallbladder, pancreas.