How do i leave certain cells unprotected on a spreadsheet

when protecting a spreadsheet how do i leave specific cells unprotected so a user can answer a drop down menu?

While reviving this old question, fix also tags (changed math to calc)

Menu/format/cells [Ctrl+1], Cell protection tab.

It works in combination with the sheet protected: Menu/Tools/Protect sheet.

So if the sheet it’s protected then cell protection it’s applied.

https://wiki.documentfoundation.org/images/5/52/CG4102-EnterEditFormatData.pdf page 33.

When you create a new spreadsheet the protected attribute is set to protected for all cells. Right click on a cell you do not want to be protected, select “Format Cells” and the “Cell Protection” tab. Uncheck the protected box.
You will notice it states here “Cell protection is only effective after the current sheet has been protected.”