Respiratory organs present in spider is
A) Skin
B) Book lungs
C) Lungs
D) Gills

Hint:The phylum arthropods consist of the highest number of organisms. They are found in almost all habitats. They bear different characteristics that separate them from other organisms.

Complete answer:
To answer this question, we first understand about the spiders belonging to phylum arthropods. The organisms of the phylum arthropods have tough exoskeletons, segmented bodies with jointed legs. The exoskeleton is the outer covering found in insects that protect the outer surface of the organism and maintain the muscle attached with it. The organism of phylum vertebrates consists of endoskeletons that mean they consist of skeletons inside the body that give the body its structure by holding the organs and protecting them. It consists of mineralized tissue that enables the muscle movement attached with it.
Now, the spiders belong to class Arachnida. It has cephalothorax, abdomen, and eight pairs of legs. The anterior pairs of appendages are modified as mouthparts that is, chelicerae. The second pair of appendages, that is, pedipalps involved in holding and sensing the prey. They have two types of respiratory organs found in the arachnids that are, book lungs and tracheae. The book lung is the hard pockets found in the under part of the abdomen, the gas gets diffused between the hemolymph that is circulating inside the lamellae. The tracheal system comprises many tubes that open to the exterior by paired respiratory pores same as in insects.

Thus, the correct answer is option ‘B’. Book lungs.

Note:Gills are the respiratory part of phylum amphibians, reptiles, and fishes. The skin is a respiratory organ for many invertebrates. A lung is the respiratory organs found in higher animals like humans. Humans have lungs where the gases get filtered and oxygen gets mixed with blood.