Which one of the following epithelium forms the inner layer of urinary bladder of animals?

Transitional epithelium is observed in the inner lining of the urinary bladder of most of the animals. 

Transitional epithelium (urothelium) has a variable appearance (transitional). In relaxed or unstretched state, looks like stratified cuboidal epithelium, except apical layer cells tend to be large and rounded. As tissue is stretched, cells become flatter, giving the appearance of stratified squamous epithelium. This allows urinary organs to stretch and maintain protective lining while holding variable amounts of fluid without rupturing.