<prompt> Most efficient antigen presenting cell in the skin -Dendritic cellMacrophagesLangerhans cellKupffer cells  <response>: Langerhans cells are dendritic cells antigen-presenting immune cells of the skin and mucosa, and contain large organelles called Birbeck granules. They are present in all layers of the epidermis except the stratum corneum, which protects against infections, and are most prominent in the stratum spinosum. Reff: Ananthanarayanan Panikers textbook of microbiology 9th edition pg: 138 