7. 發炎性大腸疾病(inflammatory bowel disease)包括克隆氏症(Crohn's disease簡稱CD)和潰瘍性腸炎(ulcerative colitis簡稱UC)，容易有腸道以外的表現(extraintestinal manifestation)。下列何種腸道外表現較常見於CD？(1)pyoderma gangrenosum (2)ankylosing spondylitis (3)primary sclerosing cholangitis (4)episcleritis (5)peripheral arthritis (A) (1)+(2)+(3) (B) (2)+(3)+(4) (C) (3)+(4)+(5) (D) (2)+(4)+(5) (E) (1)+(3)+(4)