Question: Ducks live near ponds and lakes. The shape of a duck's foot helps it swim and walk on muddy ground. Which factor is most important in determining the shape of a baby duck's foot?

  Options: 
 A. the shape of the parent ducks' feet
 B. the temperature of the pond water
 C. the amount of mud in the bottom of the pond
 D. the amount of rain that fell before the duck was born
Answer: A