When multiple objects are selected, how do you deselect just one of them?
Shift-click the object you want to deselect
Hold down the Option (Mac) or Alt (Windows) key and click the object you want to deselect.
Press Command+Shift+A (Mac) or Ctrl+Shift+A (Windows) and click the object you want to deselect.
Use the Lasso tool to deselect the unwanted object.