Choose the correct answer

III choose the correct answer
 5 You....put anything  on the shelves until the glue has set advance.
 A, couldn't   B muctn't.   C. Don't have to. D needn't
6 I......my best suit to the party yesterday; everyone else was very casually dressed
 A needn't wear.  B. Musn't wear.  C needdn't have worn .   D  mustn't have worn