A homologous structure is an organ, framework, or body part that shares a typical heritage in different creatures and few instances are the arm of a human, the wing of a flying creature or a bat, the leg of a puppy and the flipper of a dolphin or whale are homologous structures.
So, the correct option is ' Paddle of whale, front legs of horse and arms of humans/legs of duck, hind limbs of pig, hind limbs of kangaroo'.