I have a function that is adding blank dropdowns (selects) to a table.
The first row of my table shows a dropdown ("d1") with a list of options to select.

Can someone tell me how I can manage that by click on a button the list of options from d1 gets copied to a specific other dropdown (e.g. "d2") so that in the end both dropdowns show exactly the same values ?

<select id="d1">
<option value="red">red</option>
<option value="green">green</option>
<option value="blue">blue</option>

<select id="d2">
Many thanks in advance for your help,