A 19-year-old woman who prefers not to take medication uses a diffuser with lavender essential oil to help her calm down and fall asleep at night. Which biologically based therapy is she using?

Choice A reason: Herbal therapy refers to consuming plant-based remedies orally or topically, rather than inhaling essential oils. Choice B reason: Supplements are ingested substances, such as minerals or nutraceuticals, not inhaled essential oils. Choice C reason: Vitamins are micronutrients taken orally to address deficiencies, not used via diffusers for relaxation. Choice D reason: Aromatherapy involves the inhalation of essential oils, like lavender, to produce physiological and psychological benefits, such as relaxation and improved sleep.