The body cavity present in a cockroach is called .......

Identify $X, Y$ and $Z$ in the given figure of the male reproductive system of a cockroach.

Mark the odd one in each series:
Protonema; mesothorax; metathorax; coxa

Read the following statements and choose the correct option:
$(A)$ The cockroach nervous system consists of a series of fused,segmentally arranged ganglia.
$(B)$ Ganglia are joined in the cockroach by paired longitudinal connectives on the ventral side.
$(C)$ The nervous system is present on the dorsal side of the cockroach.
$(D)$ In the cockroach,the total number of ganglia is nine.

Which of the following does not take part in excretion in a cockroach?

Select the incorrect option regarding the nervous system of a cockroach.