Final answer:
Tight junctions prohibit paracellular transport by creating a watertight seal between adjacent animal cells, preventing materials from leaking between them.
Step-by-step explanation:
The type of junctional complex that will prohibit paracellular transport is A. tight junctions. Tight junctions create a watertight seal between two adjacent animal cells, holding the cells tightly against each other with proteins like claudins and occludins. This tight adhesion prevents materials from leaking between the cells. As a result, substances cannot pass through the space between the cells, ensuring that the epithelial tissues, such as those lining the urinary bladder, can act as effective barriers against the external environment.