Display default select inputs properly

I have several columns in my datatable that use the select inputs dropdowns. I used searchcols to force three of those columns to choose a default value. This works in theory; however, even though that value is searched, the dropdown displays the blank (or 'all') option and doesn't actually select the intended value - it's just running a search in that column. This has multiple user problems. How can I make it so the intended value is selected by default? Additionally, can I select multiple inputs on page load, or will I need a plugin for that? Here's my code:

initComplete: function () {
                    this.api().columns([3,4,5,6,14,15,16,17]).every( function () {
                        var column = this;
                        var select = $('<select><option value=""></option></select>')
                            .appendTo( $(column.header()).empty() )
                            .on( 'change', function () {
                                var val = $.fn.dataTable.util.escapeRegex(
                                    $(this).val()
                                );

                                column
                                    .search( val ? ''+val+'$' : '', true, false )
                                    .draw();
                            } );

                        column.data().unique().sort().each( function ( d, j ) {
                            select.append( '<option value="'+d+'">'+d+'</option>' )
                        } );
                    } );
                },

                "searchCols": [
                    null,
                    null,
                    null,
                    null,
                    null,
                    null,
                    null,
                    null,
                    null,
                    null,
                    null,
                    null,
                    null,
                    null,
                    { "search": "N", "escapeRegex": false },
                    null,
                    { "search": "B", "escapeRegex": false },
                    { "search": "75", "escapeRegex": false },
                  ]