Why did Elizabeth turn down Mr. Collins proposal? Was she right in doing so? Why did Mr. Bennet demand that her daughter accept?

Remember that the Bennett parents really want their daughters to marry as "well" as they can. That means finding a man of relative wealth and social status. Mr. Collins, more or less, fit this bill. Check out this link below:

https://ca.answers.yahoo.com/question/index?qid=20081020130315AADgeIH