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<html><head> <style> select { width: 200px; } option { padding: 0; width: 50%; background-color: cyan; } </style></head><body> <select size="3"> <option style="margin-right: auto;">left</option> <option style="margin-left: auto;">right</option> <option style="margin-left: auto; margin-right: auto;">center</option> </select> </body></html>