JSFiddle - React, Tailwind, and code Playground
HTML
<select id="Bname">
<option value="">Please Select</option>
<option value="1" data-address="Address 1" data-suburb="Suburb 1" data-state="State 1">Option 1</option>
<option value="2" data-address="Address 2" data-suburb="Suburb 2" data-state="State 2">Option 2</option>
<option value="3" data-address="Address 3" data-suburb="Suburb 3" data-state="State 3">Option 3</option>
<option value="4" data-address="Address 4" data-suburb="Suburb 4" data-state="State 4">Option 4</option>
<option value="5" data-address="Address 5" data-suburb="Suburb 5" data-state="State 5">Option 5</option>
</select>
<div>
<label>Address</label> <input type="text" name="Badress" />
<label>Suburb</label> <input type="text" name="PCsuburb" />
<label>State</label> <input type="text" name="PCstate" />
</div>
JavaScript
$('#Bname').change(function() {
selectedOption = $('option:selected', this);
$('input[name=Badress]').val( selectedOption.data('address') );
$('input[name=PCsuburb]').val( selectedOption.data('suburb') );
$('input[name=PCstate]').val( selectedOption.data('state') );
});