Final answer:
The correct statement about teratoma is that it often contains skin and skin appendages, such as teeth.
Step-by-step explanation:
Of the given statements, the correct one about teratoma is: 3) It often contains skin and skin appendages, such as teeth, etc. Teratomas are tumors that can contain multiple types of tissues, including skin, hair, teeth, and even more complex structures like bone and muscle. They are most commonly found in reproductive organs and usually occur in young adults, rather than postmenopausal women. Teratomas can be either benign or malignant, but they are usually benign.