هل هذا خطأ مطبعى ام الجملة صحيحة من الورك بوك

[فيونه]

Workbook - page 80 - Exercise 1

The nurse, whose/who responsibility it is to look after
young children, has worked at the hospital for ten years

ما راى الاساتذة الافاضل فى وجود ( it ) فى الجملة