关于免疫球蛋白，下列描述错误的是（）

A.是具有抗体活性的球蛋白

B.由浆细胞产生

C.存在于血液、体液及外分泌液中

D.不存在于细胞膜上

E.有特异性识别抗原的功能

OOO Consult offers business advisory services. The company decided to make major improvements to the reception rea of its main offi ce and entered into a contract with OOO Fix to carry out the necessary work.In order to install new lighting, employees of OOO Fix had to dig a hole in the area where customers wait for their ppointments. During the course of this work, Anna, a customer of OOO Consult, suffered injury after tripping on bricks hat had been removed by the workers and left on the fl oor. Anna subsequently had to take one month’s sick leave and ad to pay for medical care.Required:

(a) Explain the rationale that will be applied by the courts when assessing the non-contractual obligations incurred n respect of Anna’s injuries. (4 marks)