Complete analogous pair - Snake : Fang : : Bee : ?

D. STING

Complete analogous pair - Pongee : Silk : : Shallot : ?

A. BOAT

Look at this series: 1.5, 2.3, 3.1, 3.9, . . .
What number should come next?

C. 4.7

Complete analogous pair - Melt : Liquid : : Freeze : ?

C. SOLID

Carnivorous : Tiger : Wolf

D. STUDENT : BOY : GIRL