This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
Gland of Zeis which open into follicles of eyelashes are: 
Select and explain. 
A. Modified sebaceous glands, B. Modified sweat glands, C. Modified lacrimal glands, D. Modified meibomian glands
A: Modified sebaceous glands
Answer: A: Modified sebaceous glands 
Explanation: Gland of Zeis are modified sebaceous glands which open into follicles of eyelashes. Gland of Moll are modified sweat glands which open into hair follicles. Meibomian glands are modified sebaceous glands, about 20-30 in each lid. Ref: Review of Ophthalmology A.K.Khurana, 5th Ed, page 9-10