removing nodes to parent based on all child nodes not

I am new to XSLT and I am trying to clean up an XML file built from a
mainframe generated text file that contains all possible elements for all
nodes. In the new XML I only need to copy the nodes that actually have
elements that have text values. Is there a way to test the deepest child of an
element for text value and then copy all it's ancestors back to the root? For
example, in the attached input under the element <Entity> only <Individual> or
<Business> should exist and not both. If any child elements have text value
for the element <Individual> all child nodes should be copied, while the
<Business> element and all it's child nodes should not be copied to the new
XML file. See example input and output files.

Input


<Registration>
 <UserName>DID1901</UserName>
 <ActivityType>25</ActivityType>
 <ActivityDate>2008-10-30T12:10:26</ActivityDate>
 <RegistrationCounty>19</RegistrationCounty>
 <Registrants>
  <Registrant>
   <Entity>
    <Individual>
     <Prefix/>
     <FirstName></FirstName>/>
     <LastName></LastName>/>
     <Middle/>
     <Suffix/>
    </Individual>
    <Business>
     <MailingAddress>
      <Address>
       <MailingAddressType/>
       <MailingAddressLine1>123 Street</MailingAddressLine1>
       <MailingAddressLine2/>
      </Address>
     </MailingAddress>
    </Business>
   </Entity>
  </Registrant>
 </Registrants>
</Registration>



Output


<Registration>
 <UserName>DID1901</UserName>
 <ActivityType>25</ActivityType>
 <ActivityDate>2008-10-30T12:10:26</ActivityDate>
 <RegistrationCounty>19</RegistrationCounty>
  <Registrants>
  <Registrant>
   <Entity>
    <Individual>
     <Prefix/>
     <FirstName>Joe</FirstName>/>
     <LastName>Doe</LastName>/>
     <Middle/>
     <Suffix/>
    </Individual>
   </Entity>
  </Registrant>
 </Registrants>
</Registration>