<Tr> <Td> 17 </Td> <Td> Af: Egypt </Td> <Td> 1845000 </Td> <Td> 2007 est . </Td> <Td> </Td> </Tr> <Tr> <Td> 27 </Td> <Td> Af: Tunisia </Td> <Td> 664000 </Td> <Td> 2007 est . </Td> <Td> Australia </Td> </Tr> <Tr> <Td> 31 </Td> <Td> Af: Sudan </Td> <Td> 466100 </Td> <Td> 2007 est . </Td> <Td> Ecuador </Td> </Tr> <Tr> <Td> 33 </Td> <Td> Af: Eq. Guinea </Td> <Td> 368500 </Td> <Td> 2007 est . </Td> <Td> Vietnam </Td> </Tr>

Which of the following constitutes the largest climate zone in sub-saharan africa