Final answer:
Intracytoplasmic bacteria in enterocytes are detected by Toll-like receptors, which are crucial for initiating an immune response against pathogens.
Step-by-step explanation:
Intracytoplasmic bacteria in enterocytes of the gastrointestinal tract are detected by c) Toll-like receptors. Lysosomes play an essential role in the innate immune response by using their hydrolytic enzymes to destroy disease-causing organisms that enter the cell, a process exemplified in macrophages during phagocytosis. However, the initial detection of intracellular pathogens, like bacteria within enterocytes, typically involves Toll-like receptors (TLRs), which recognize pathogen-associated molecular patterns and initiate an immune response.