Which kingdom includes only photosynthetic organisms w.r.t. Whittaker classification system ?

Explanation

**Step-by-Step Solution:**

1. **Understanding the Whittaker Classification System**: The Whittaker classification system, proposed in 1969, categorizes living organisms into five kingdoms based on various criteria, including cell type, complexity, mode of nutrition, and ecological roles.

2. **Identifying the Five Kingdoms**: The five kingdoms in the Whittaker classification are:
- Monera: Prokaryotic organisms (bacteria).
- Protista: Unicellular eukaryotic organisms, some of which can photosynthesize.
- Fungi: Multicellular and unicellular eukaryotic organisms that are heterotrophic.
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