IF Statement and Data Validation List

I have Data Validation lists in multiple columns on a spreadsheet.  The Data Validation lists includes Yes, No, N/A, or a blank cell.  I inserted an IF statement for the following:

1) If the answer to Question #1 is Yes, then I would like the cells for Question #2 through #4 to remain blank.

2) If the answer to Question #1 is No, then I would like the cells for Question #2 through #4 to display N/A. 

I figured out point 2 mentioned above but I cannot figure out point 1.  When I try to include "" in the IF statement for when the statement is false, I receive the below error message.