Fungi can be distinguished by

Options

A. absence of chlorophyll
B. presence of chitin in cell wall
C. presence of plastids
D. both (a) and (b).

Explanation

### Step-by-Step Solution:

1. **Understanding Fungi**: Fungi belong to a unique kingdom of heterotrophic organisms. This means they cannot produce their own food and rely on other organisms for nutrition.

2. **Absence of Chlorophyll**: One of the key characteristics of fungi is the absence of chlorophyll. Chlorophyll is a pigment found in photosynthetic organisms that allows them to capture light energy for photosynthesis. Since fungi do not have chlorophyll, they cannot perform photosynthesis and are therefore classified as heterotrophs.

3. **Presence of Chitin in Cell Wall**: Fungi have a cell wall that is made of chitin. This distinguishes them from plants, which have cell walls made of cellulose. The presence of chitin is a significant feature that helps in identifying fungi.

4. **Presence of Plastids**: Plastids are organelles found in plants and some protists that are involved in photosynthesis and storage of products. However, fungi do not possess plastids. This further supports the idea that fungi are not involved in photosynthesis.

5. **Conclusion**: Based on the characteristics discussed, fungi can be distinguished by the absence of chlorophyll and the presence of chitin in their cell walls. Therefore, the correct answer to the question is "both A and B".