Question

Fish is to water as a _____ is to air.
a. Duck
b. Bird
c. Butterfly
d. Sparrow

Answer 1

Fish is to water as a bird is to air.

Duck and Sparrow are types of birds and it's not really logical for it to be butterfly, I don't think.

Answer 2

Bird, because it is a general term that recognizes that birds fly in air, while fish swim in water.