In cockroaches,$O_2$ is transported to the tissues by which of the following?

Identify the odd one out.

Which of the following is present as an excretory organ in cockroaches?

In cockroaches,in what form do the body cells primarily discharge their nitrogenous waste into the hemolymph?

Which of the following statement$(s)$ is/are correct regarding the excretory system of a cockroach?
$(i)$ Excretion is performed by Malpighian tubules.
$(ii)$ They absorb nitrogenous waste products and convert them into uric acid,which is excreted out through the hindgut.
$(iii)$ In addition,fat body,nephrocytes,and urecose glands also help in excretion.

The nerve cord in a cockroach is: ........