Cannot use the same TMPL_VAR to select ALL options.
Only one select can be selected in this case. If preselection of search type is
desired, I recommend a clean implementation w/ jquery instead of adding a conditional
for each select. Please note, that is the only good way to get multiple preselections,
since the same .inc file will be used in each case. So a single variable like
<TMPL_IF NAME="index_bc_selected">
cannot be used, since it would set for ALL (3) advanced search dropdowns.