One evening, Sarah started her homework at half past four.  She finished it at twenty minutes to six.  How long did her homework take? 
选项为:A:$$1$$ hour $$10$$ minutes  B:$$1$$ hour $$50$$ minutes  C:$$50$$ minutes  D:$$1$$ hour $$30$$ minutes  E:$$1$$ hour $$20$$ minutes  请回答其中一个选项.