using href links inside tag

Answer 1

Use a real dropdown menu instead: a list (ul, li) and links. Never misuse form elements as links.

Readers with screen readers usually scan through a automagically generated list of links – the’ll miss these important information. Many keyboard navigation systems (e.g. JAWS, Opera) offer different keyboard shortcuts for links and form elements.

If you still cannot drop the idea of a select don’t use the onchange handler at least. This is a real pain for keyboard users, it makes your third item nearly inaccessible.