Concept:
Conservation biology and animal classification involve concepts such as coelom formation, biodiversity hotspots and conservation strategies.
We must identify the statements that are incorrect.
Step 1: Examine Statement I.
Schizocoelomates and enterocoelomates possess a true coelom.
Acoelomates completely lack a coelom.
Therefore it is incorrect to say that schizocoelomates and enterocoelomates are together called acoelomates.
Hence Statement I is incorrect.
Step 2: Examine Statement II.
Biodiversity hotspots are regions showing:
• High species richness
• High endemism
This definition is correct.
Hence Statement II is correct.
Step 3: Examine Statement III.
Threatened species are recorded in the Red Data Book.
This statement is correct.
Step 4: Examine Statement IV.
Cryopreservation involves preservation outside the natural habitat at extremely low temperatures.
Therefore it is an example of ex-situ conservation and not in-situ conservation.
Hence Statement IV is incorrect.
Step 5: Final conclusion.
Incorrect statements:
\[
I \text{ and } IV
\]
Therefore option (A) is correct.