I've realized that Chrome, it seems, will not allow me to hide <option> in a <select>. Firefox will.
I need to hide the <option>s that match a search criteria. In the Chrome web tools I can see that they are correctly being set to display: none; by my JavaScript, but once then <select> menu is clicked they are shown.
How can I make these <option>s that match my search criteria NOT show when the menu is clicked?