# * <tt>:multiple</tt> - If set to true the selection will allow multiple choices.
# * <tt>:disabled</tt> - If set to true, the user will not be able to use this input.
# * <tt>:include_blank</tt> - If set to true, an empty option will be created.
# * <tt>:include_blank</tt> - If set to true, an empty option will be created. If set to a string, the string will be used as the option's content and the value will be empty.
# * <tt>:prompt</tt> - Create a prompt option with blank value and the text asking user to select something.
# * <tt>:selected</tt> - Provide a default selected value. It should be of the exact type as the provided options.
# * Any other key creates standard HTML attributes for the tag.