<label>What is the school type? Select one</label>
<radio> inputs present the user with a series of 'radio buttons' of which they can select only one.
As with <select1> and <select> this allows you to pre-define choices and this helps you ensure that data collected adheres to what you have specified.
Every <radio> MUST contain one <label> tag which specifies the question presented to a user.
You can then specify as many <item> tags as you require. However, each <item> MUST contain one <label> and one <value> tag. The <label> specifies the text the user sees as a choice and the <value> specifies what is stored in the database when a user selects this choice.
<radio> tags are essentially similar in concept to <select1> inputs, however all choices are presented to a user at once, and this in some cases may ease the presentation of your question choices.
You can of course also specify the required="true" attribute within the radio tag