input: Text: BIG ANCESTOR By F. L. WALLACE Illustrated by EMSH Man's family tree was awesome enough to give every galactic race an inferiority complex—but then he tried to climb it! In repose, Taphetta the Ribboneer resembled a fancy giant bow on a package. His four flat legs looped out and in, the ends tucked under his wide, thin body, which constituted the knot at the middle. His neck was flat, too, arching out in another loop. Of all his features, only his head had appreciable thickness and it was crowned with a dozen long though narrower ribbons. Taphetta rattled the head fronds together in a surprisingly good imitation of speech. "Yes, I've heard the legend." "It's more than a legend," said Sam Halden, biologist. The reaction was not unexpected—non-humans tended to dismiss the data as convenient speculation and nothing more. "There are at least a hundred kinds of humans, each supposedly originating in strict seclusion on as many widely scattered planets. Obviously there was no contact throughout the ages before space travel— and yet each planetary race can interbreed with a minimum of ten others! That's more than a legend—one hell of a lot more!" "It is impressive," admitted Taphetta. "But I find it mildly distasteful to consider mating with someone who does not belong to my species." "That's because you're unique," said Halden. "Outside of your own world, there's nothing like your species, except superficially, and that's true of all other creatures, intelligent or not, with the sole exception of mankind. Actually, the four of us here, though it's accidental, very nearly represent the biological spectrum of human development. "Emm
  Question: What is ironic about Taphetta's contempt for mating among species?
  
   (A) Taphetta can only survive if they mate with another species
   (B) Taphetta is actually jealous about other species' ability to intermix
   (C) Taphetta is likely a result of mating among species
   (D) Taphetta is biologically unable to mate with other species 
  Answer:
output: Taphetta is biologically unable to mate with other species