Find the correct statement

Options

A. Centric diatoms are bilaterally symmetrical
B. Pennate diatoms are radially symmetrical
C. Auxospores are rejuvenatory spores
D. Dinoflagellates are mostly fresh water organisms

Answer

To find the correct statement among the options provided, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Analyze the First Statement:**
- The first statement claims that "centric diatoms are bilaterally symmetrical."
- **Evaluation:** Centric diatoms are actually radially symmetrical, not bilaterally symmetrical. Therefore, this statement is **incorrect**.

2. **Analyze the Second Statement:**
- The second statement claims that "pinnate diatoms are radially symmetrical."
- **Evaluation:** Pinnate diatoms are bilaterally symmetrical, not radially symmetrical. Thus, this statement is also **incorrect**.

3. **Analyze the Third Statement:**
- The third statement claims that "auxospores are rejuvenatory spores."
- **Evaluation:** Auxospores are indeed rejuvenatory spores that play a significant role in the growth processes and sexual reproduction. This statement is **correct**.

4. **Analyze the Fourth Statement:**
- The fourth statement claims that "dinoflagellates are mostly freshwater organisms."
- **Evaluation:** Dinoflagellates are primarily marine organisms, with many species found in saltwater environments. Therefore, this statement is **incorrect**.

### Conclusion:
The only correct statement among the options given is the third statement: "Auxospores are rejuvenatory spores."