Answer :

To determine the correct formula for diphosphorus tetrabromide, we need to break down the name into its chemical components and understand the prefixes used in naming the compound.

1. Identify the elements involved:
- "Diphosphorus" indicates the presence of phosphorus (P).
- "Tetrabromide" indicates the presence of bromine (Br).

2. Understand the prefixes:
- The prefix "di-" means two.
- The prefix "tetra-" means four.

3. Construct the formula base on the given prefixes:
- "Diphosphorus" means we have two phosphorus atoms.
- "Tetrabromide" means we have four bromine atoms.

4. Combine the elements with their respective quantities:
- Two phosphorus atoms can be noted as [tex]\( P_2 \)[/tex].
- Four bromine atoms can be noted as [tex]\( Br_4 \)[/tex].

Thus, putting these together, we get the chemical formula for diphosphorus tetrabromide as [tex]\( P_2 Br_4 \)[/tex].

Therefore, the correct answer is:
B. [tex]\( P_2 Br_4 \)[/tex]