Final answer:
In summary, the bacterium that fits the description of having branching GPB, being partially acid-fast, and capable of hydrolyzing urea is Corynebacterium diphtheriae.
Step-by-step explanation:
The question asks to identify a bacterium that has branching gram-positive bacilli (GPB), is partially acid-fast, and has the ability to hydrolyze urea. The correct answer is Corynebacterium diphtheriae. This bacterium is known for its club-shaped appearance, which can sometimes resemble branching. It is also partially acid-fast due to the presence of mycolic acid in its cell wall, which is a characteristic it shares with Mycobacterium tuberculosis, another well-known acid-fast bacterium. Corynebacterium diphtheriae can also hydrolyze urea, distinguishing it from other choices that either are not acid-fast, do not hydrolyze urea, or do not have branching GPB structures.