<prompt> Acne vulgaris primarily involves -Sweat glandsSebaceous glandHair folliclesCeruminous glands  <response>: Ans- B Sebaceous gland Acne vulgaris is a common chronic skin disease involving blockage andor inflammation of pilosebaceous units hair follicles and their accompanying sebaceous gland. Acne can present as noninflammatory lesions, inflammatory lesions, or a mixture of both, affecting mostly the face but also the back and chest. 