Here's a problem to solve: Which of these does not illustrate substances reacting to form new substances?

Among the 4 following options, which is the correct answer?

- A: H_{2}O(l) -> H_{2}O(g)
 
- B: 2H_{2} + O_{2} -> 2H_{2}O
 
- C: 2Na + Cl_{2} -> 2NaCl
 
- D: 6CO_{2} + 6H_{2}O -> C_{6}H_{12}O_{6} + 6O_{2}
 