Which of the following statements are incorrect?
(A) Digestion takes place in spongocoel in sponge
(B) Nitrogenous waste of protozoans is ammonia
(C) Leishmania is a digenetic parasite
(D) Only intracellular digestion takes place in coelenteron of cnidaria

Options

A. A, B, C
B. A, C, D
C. B, C
D. A, D

Answer

To determine which of the statements are incorrect, let's analyze each statement one by one:

1. **Statement (A): Digestion takes place in spongocoel in sponge.**
- This statement is **incorrect**. In sponges, digestion occurs intracellularly within the cells, particularly in specialized cells called choanocytes. The spongocoel is the central cavity of the sponge, but it does not serve as the site for digestion.

2. **Statement (B): Nitrogenous waste of protozoans is ammonia.**
- This statement is **correct**. Most protozoans excrete nitrogenous waste in the form of ammonia, which is a common waste product due to their aquatic habitat and the ability to diffuse ammonia directly into the surrounding water.

3. **Statement (C): Leishmania is a digenetic parasite.**
- This statement is **correct**. Leishmania is indeed a digenetic parasite, meaning it has two different hosts in its life cycle: a mammalian host (where it causes disease) and an insect vector (typically sandflies).

4. **Statement (D): Only intracellular digestion takes place in coelenteron of cnidaria.**
- This statement is **incorrect**. In cnidarians, digestion occurs both intracellularly (within the cells) and extracellularly (in the gastrovascular cavity, which is referred to as the coelenteron). Therefore, stating that only intracellular digestion occurs is misleading.

Now, summarizing the findings:
- **Incorrect Statements**: (A) and (D)
- **Correct Statements**: (B) and (C)

### Final Answer:
The incorrect statements are **(A) and (D)**.