Ruth Has a Home Office That She Shares with Her

Ruth has a home office that she shares with her husband, Barret. She keeps track of her business profits and expenses in several worksheets.
-Ruth has fully tested all of the formulas in her worksheet and the correct results appear.Ruth provides a copy of the worksheet file to Barret so he can use it for his business calculations.As a user,Barret can make changes only to certain cells.What did Ruth do to ensure the other cells cannot be altered by user Barret?

A) unlock the user cells and then unprotect the worksheet
B) unlock the user cells and then protect the worksheet
C) lock the user cells and then unprotect the worksheet
D) lock the user cells and then protect the worksheet