Choose the correct combinations
(a) Tubellaria-mostly free living flat worms with - convoluta mucus formating rhabdites in body wall
(b) Trematoda - Comkmonly called flukes and bear - Bilharzia two suckers
(c ) Cestoda -Ecto - and endoparasite , body segmented -Echinococcus
(d) Phasmidia - Amphids -formating chemorceptor fucation -Trichuris

Options

A. (b) and (c )
B. (a) and (b)
C. (a),(c ) and (d)
D. (a) ,(b) and (d).

Answer

To solve the question regarding the correct combinations of classifications in Platyhelminthes, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Analyzing Option (a): Tubellaria**
- **Statement**: Tubellaria are mostly free-living flatworms with convoluted mucus forming rhabdites in the body wall.
- **Explanation**: Tubellaria indeed consists of mostly free-living flatworms. Rhabdites are specialized cells that produce mucus, which serves as a defense mechanism. This statement is correct.
- **Conclusion**: Option (a) is correct.

2. **Analyzing Option (b): Trematoda**
- **Statement**: Trematoda are commonly called flukes and bear Bilharzia with two suckers.
- **Explanation**: Trematoda includes flukes, which are characterized by having two suckers for attachment. Bilharzia, also known as schistosomiasis, is caused by a type of fluke. This statement is also correct.
- **Conclusion**: Option (b) is correct.

3. **Analyzing Option (c): Cestoda**
- **Statement**: Cestoda are ecto- and endoparasites, body segmented - Echinococcus.
- **Explanation**: Cestoda, or tapeworms, are primarily endoparasites (not ectoparasites). They are segmented, and Echinococcus is a genus of tapeworms. The mention of them being ectoparasites makes this statement incorrect.
- **Conclusion**: Option (c) is incorrect.

4. **Analyzing Option (d): Phasmidia**
- **Statement**: Phasmidia have amphids forming chemoreceptor function - Trichuris.
- **Explanation**: Phasmidia refers to a group of roundworms (Nematodes), and Trichuris is a genus of whipworms, which belong to this group. However, the statement mixes classifications as Phasmidia is not part of Platyhelminthes. Therefore, this statement is incorrect.
- **Conclusion**: Option (d) is incorrect.

### Final Conclusion:
The correct combinations are options (a) and (b). Therefore, the answer is that options A and B are correct.

---