根据以下材料，回答 Hair loss can be destructive for themillions of men and women who experience it. Now scientists are reporting thata substance from honeybee hives might contain clues for developing a potentialnew therapy. They found that the material, called propolis, encouraged hairgrowth in mice. The study appears in A CS′ Journal of Agricultural and FoodChemistry. Ken Kobayashi and colleagues note that propolis is a resin-likematerial that honeybees use to seal small gaps in their hives. Not only does itwork as a physical barrier, but it also contains active compounds that fightfungal and bacterial invasions. People from ancient times had noticed propolis′special properties and used it to treat tumors, inflammation and wounds. Morerecently, research has shown that the substance promotes the growth of certaincells involved in hair growth though no one had yet tested whether that in turnwould result in new locks. Kobayashi ′ s team wanted to find out. When the researchers tested propolis onmice that had been shaved or waxed, the mice that received the treatment regrewtheir fur faster than those that didn′t. The scientists also noticed that afterthe topical application, the number of special cells involved in the process ofgrowing hair increased. Although they tried the material on mice that couldgrow fur rather than balding mice, the researchers note that hair lossconditions often result from abnormal inflammation. Propolis contains anti-inflammatorycompounds, so they expert it could help treat balding conditions. They add that further testing is needed tosee if the beehive material affects human hair follicles. What may cause hair loss according tothe passage?
A.Severe inflammation. B.Headache. C.Fungus. D.Cancer.