The correct answer is option 3, heterocercal. The type of tail found in sharks is known as heterocercal. This type of tail is characterized by a longer upper lobe and a shorter lower lobe. The caudal vertebrae and the cartilaginous fin rays are asymmetrically placed in the tail, which allows for greater stability and maneuverability in the water. Option 1, protocercal, refers to a type of tail found in primitive fish. Option 2, homocercal, refers to a type of tail found in bony fish, where the upper and lower lobes are of equal length. Option 4, diphycercal, refers to a type of tail found in lungfish, where the vertebral column extends to the upper lobe of the tail.