Which one of the following is a character of all amphibians, without any exception?

In amphibians, skin is moist and is without scales. Minute cycloid scales are embedded in the dermis in apodans (e.g., Ichthyophis). Limbs are absent in apodans (e.g., Ichthyophis). Tail is present in urodeles (e.g., Salamandra). The eyes have eyelids.