you are using .textContent
and it is not supported IE8 and below. Change it to innerHTML and it should work.
See .textContent
for (var Id in Options.items) {
var option = document.createElement('option');
option.value = Id;
option.innerHTML = Options.items[Id]; //<--here
if (Options.defaultId === Id) {
option.setAttribute('selected', 'selected');
}
select.appendChild(option);
}