Which is wrong

Options

A. Contractile vocuoles regulate osmoregulation in marine protozoan
B. Euglena is holophytic protozoan
C. Trypanosoma belongs to class Mastigophora
D. Class sporozoa includes Plasmodium.

Answer

**Step-by-Step Solution:**

1. **Understanding the Options:**
- The question asks to identify which statement is incorrect among the given options related to protozoans.

2. **Analyzing Each Option:**
- **Option A:** "Contractile vacuoles regulate osmoregulation in marine protozoans."
- This statement is incorrect. Contractile vacuoles are primarily found in freshwater protozoans, where they help in osmoregulation by expelling excess water. Marine protozoans generally do not require contractile vacuoles due to the saline environment.

- **Option B:** "Euglena is a holophytic protozoan."
- This statement is correct. Euglena can perform photosynthesis and obtain nutrients from its environment, making it holophytic.

- **Option C:** "Trypanosoma belongs to class Mastigophora."
- This statement is also correct. Trypanosoma is a flagellated protozoan and falls under the class Mastigophora.

- **Option D:** "Class Sporozoa includes Plasmodium."
- This statement is correct as well. Plasmodium is a well-known genus within the class Sporozoa, which is characterized by its spore-like stage in the life cycle.

3. **Identifying the Incorrect Statement:**
- From the analysis, it is clear that Option A is the incorrect statement regarding protozoans.

4. **Conclusion:**
- The wrong statement is: "Contractile vacuoles regulate osmoregulation in marine protozoans."