根据下列材料，请回答题
Hair Care
Whether the hair is long or short，it must be regularly brushed and regularly washed．For greasy（油性的）hair，especially if the owner lives in a town。it may be necessary to wash the head every four to five days．Those with a dry hair can usually go a little longer，but this is a matter for the individual to decide．
As for style．this must be studied according to what is the latest fashion and also to suit the individual at different times of her life．If a woman is not able to go to hairdresser very often，it is important that she chooses a style. she can easily manage for herself，and this nearly always means
that the first cut must be very standard．The same applies to permanent waving（烫发）．I think that this should be carried out three or four times a year，SO that the hair never gets out of hand．
One thing would be remembered though，that is，whatever you apply to the head can have some effect upon the skin and therefore anything strong should be used with care．Or you may use milder products．
Young people who has spots or skin troubles on their face should take particular care to en． sure that the hair is both clean and does not come into contact with the affected piece of skin．Hair is very difficult to keep completely clean and therefore anyone running their hands through their hair and afterwards touching their face，or letting their hair fall over their faces，might spread infection from one place to another．s
Good hair does a lot to the effect of a face，SO if you want to look charming，please start with your hair．
According to the text，the most basic thing to do in hair care isC． 查看材料

A. to go to hairdressers very often
B. to choose milder products for the hair
C. to wash and brush the hair regularly
D. to keep the hair away from the skin trouble