The correct option is B Auxospores
Rejuvenating spores of diatoms are Auxospores. In certain species of diatoms, auxospores are specialised cells that are produced at key stages in their cell cycle or life history. They typically play a role in growth processes, sexual reproduction or dormancy. Auxospores are involved in re-establishing the normal size in diatoms because successive mitotic cell divisions lead to a decrease in cell size.