Mention the characteristics of the class Hydrozoa.

Study the following statements
A) Corallium rubrum is the precious red stone coral that belongs to Scyphozoa
B) Renette gland is an excretory gland found in round worms
C) Tubifex is an aquatic annelid
D) In chilopods, maxillae are modified into gnathochilarium

Among the above, the incorrect statements are

Match List$-\mathrm{I}$ with List$-\mathrm{II}$.

Match the following.

The correct answer is:

Represent the union of two sets by Venn diagram for each of the following.

$X=\{x | x$ is a prime number between $80$ and $100\}$

$Y=\{y | y$ is an odd number between $90$ and $100\}$

Identify the following four animals (A, B, C and D) given below. Which one of these is not correctly identified in the option given along with its correct taxonomic group and their common name?