Refer to the given reaction.
`RuBP+O_(2)underset("oxygenase")overset("RuBP")rarr"Phosphoglyceric acid"+"Phosphoglycolic acid"`
It is the first reaction of

Options

A. `C_(3)` pathway
B. `C_(4)` pathway
C. `C_(2)` pathway
D. glycolysis.

Explanation

### Step-by-Step Solution:

1. **Identify the Reaction Components**: The reaction provided is between Ribulose bisphosphate (RuBP) and oxygen (O₂). The products of this reaction are phosphoglyceric acid (PGA) and phosphoglycolic acid (PGAc).

2. **Recognize the Role of RuBP**: RuBP can function as both a carboxylase and an oxygenase. In this reaction, it is acting as an oxygenase, which means it is catalyzing the reaction with oxygen.

3. **Understand the Products**: The products of this reaction include:
- Phosphoglyceric acid (PGA), which is a 3-carbon compound.
- Phosphoglycolic acid (PGAc), which is a 2-carbon compound.

4. **Connect to Photorespiration**: This reaction is a part of a process known as photorespiration. During photorespiration, RuBP reacts with oxygen instead of carbon dioxide, leading to the formation of these two products.

5. **Classify the Process**: The outcome of this reaction is collectively referred to as the C2 pathway or C2 photosynthesis, due to the formation of the 2-carbon compound (phosphoglycolic acid).

6. **Conclusion**: Thus, the given reaction is the first step of photorespiration, where RuBP acts as an oxygenase in the presence of oxygen.