Oxygenation takes place during photorespiration/carboxylation.

Explanation

To answer the question of whether oxygenation takes place during photorespiration or carboxylation, we can follow these steps:

### Step-by-Step Solution:

1. **Define Photorespiration and Carboxylation**:
- Photorespiration is a process that occurs when the enzyme RuBisCO (Ribulose-1,5-bisphosphate carboxylase/oxygenase) catalyzes the reaction of RuBP (Ribulose bisphosphate) with oxygen instead of carbon dioxide.
- Carboxylation, on the other hand, refers to the process where RuBisCO catalyzes the reaction of RuBP with carbon dioxide to form 3-phosphoglycerate (3-PGA), which is the first step in the Calvin cycle.

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