The answer is A. Ear.
The ear is the organ of hearing and balance. It is located on the side of the head and consists of three parts: the outer ear, the middle ear, and the inner ear. The outer ear is made up of the ear canal and the eardrum. The middle ear is a small, air-filled space that contains three small bones called the ossicles. The inner ear is a fluid-filled space that contains the cochlea, the vestibular system, and the auditory nerve. The cochlea is responsible for hearing, and the vestibular system is responsible for balance.
The kidney is a bean-shaped organ that is located in the lower back. It is responsible for filtering waste products from the blood and producing urine. The lungs are two spongy organs that are located in the chest. They are responsible for exchanging oxygen and carbon dioxide with the blood. The liver is a large, lobed organ that is located in the upper right abdomen. It is responsible for many important functions, including digestion, metabolism, and detoxification.
The ear is different from the other organs listed because it is not responsible for exchanging oxygen and carbon dioxide with the blood. The other organs, the kidney, lungs, and liver, are all responsible for this function.