Which of the following does not directly react with oxygen?

Options

A. Zn
B. Ti
C. PC
D. Fe

Explanation

To determine which of the given options does not directly react with oxygen, we need to analyze each option one by one.

1. **Zinc (Zn)**:
- Zinc reacts with oxygen to form zinc oxide (ZnO).
- Reaction: \( 2Zn + O_2 \rightarrow 2ZnO \)
- Conclusion: Zinc does react with oxygen.

2. **Titanium (Ti)**:
- Titanium reacts with oxygen to form titanium dioxide (TiO2).
- Reaction: \( 4Ti + O_2 \rightarrow 2TiO_2 \)
- Conclusion: Titanium does react with oxygen.

3. **Phosphorus (P)**:
- Phosphorus does react with oxygen but it is important to note that it can react in different forms (white, red, black phosphorus) and the reaction can vary. However, it is generally known that phosphorus does react with oxygen to form phosphorus oxides (like P4O10).
- Reaction: \( 4P + 5O_2 \rightarrow P_4O_{10} \)
- Conclusion: Phosphorus does react with oxygen.

4. **Iron (Fe)**:
- Iron reacts with oxygen to form iron oxides (FeO or Fe2O3).
- Reaction: \( 4Fe + 3O_2 \rightarrow 2Fe_2O_3 \)
- Conclusion: Iron does react with oxygen.

After analyzing all the options, we can conclude that all of them react with oxygen. However, if we consider the context of the question, it seems that phosphorus may not be as straightforward in its reactivity compared to the others, depending on its allotrope.

Thus, the answer to the question is that phosphorus (P) does not directly react with oxygen in the same way as the metals do.

### Final Answer:
**Phosphorus (P)** does not directly react with oxygen in a straightforward manner compared to the other elements listed.