Okay, let's start with an example.

<select id = "selection1">
    <option value = "1" id = "1">Number 1</option>
    <option value = "2" id = "2">Number 2</option>
    <option value = "3" id = "3">Number 3</option>
</select>

Now from here, we have a dropdown with 3 options.
What I want to do now is to hide an option.

Adding style = "display:none" will not help.
The option would not appear in the dropdownlist, but using the arrow keys, you can still select it.
Essentially, it does exactly what the code says. It isn't displayed, and it stops there.

A JQuery function of $("1").hide() will not work.
Plus, I don't only want to hide the option, I want to completely remove it.

Any possibility on doing so?
Do I have to use parent/sibling/child elements? If so, I'm still not sure how.

Any help on this would be greatly appreciated. Thanks.