The quantity of titanium dioxide present in an ore may be found by means of the following reaction. $3\text{TiO}_2 + 4\text{BrF}_3 \rightarrow 3\text{TiF}_4 + 2\text{Br}_2 + 3\text{O}_2$ Which element has an increase in oxidation number in this reaction?
- Abromine
- Bfluorine
- Coxygen
- Dtitanium