An example of homologous organs is

• our arm and a dog’s fore-leg
• our teeth and an elephant’s tusks
• potato and runners of grass 
• all of the above

• a Chinese school-boy
• a chimpanzee
• a spider
• a bacterium

A Mendelian experiment consisted of breeding tall pea plants bearing violet flowers with short pea plants bearing white flowers. The progeny all bore violet flowers, but almost half of them were short. This suggests that the genetic make-up of the tall parent can be depicted as:
(a) TTWW
(b) TTww
(c) TtWW
 (d) TtWw