Which of the following animals does NOT have a backbone?

Spider

The correct answer is Option (3)- Spider

Spider is an animal that does NOT have a backbone. Spiders are classified as arachnids and belong to a group of invertebrates. Unlike frogs, humans, and pigeons, which are vertebrates and possess a backbone (vertebral column), spiders lack this bony structure. Instead, spiders have an exoskeleton and belong to a diverse group of arthropods known as arachnids.