Google Sheets Apps Script : use checkbox to copy cell content to another cell

I would like to create a function to copy cell content, within the same sheet, from two columns (A & C) to columns E & G (respectively), if a checkbox in column D is checked.

Same question if it were instead for a range of columns (A-C) being copied to columns (E-G) with checkbox still in column D.

Thank you for your helpful and insightful solution(s).