JQuery Seleccione la opción por valor
$('.id_100 option[value=val2]').attr('selected','selected');
Almabek
$('.id_100 option[value=val2]').attr('selected','selected');
$( "#myselect option:selected" ).val();$("select.country").change(function(){
var selectedCountry = $(this).children("option:selected").val();
alert("You have selected the country - " + selectedCountry);
});$(document).ready(function(){
$("select.country").change(function(){
var selectedCountry = $(this).children("option:selected").val();
alert("You have selected the country - " + selectedCountry);
}); let payment_type = $("#olca_form_submit select[name='payment_type']")
.find(":selected")
.val();$('.selDiv option[value="SEL1"]')