Tree is to Leaf as Flower is to ?

A. PETAL

Book is to Read as Movie is to ?

A. WATCH

Key is to Lock as Password is to ?

C. LOGIN

What number should replace the question mark in the series: 2, 6, 12, 20, ?

B. 42

What is the next number in the series: 1, 4, 9, 16, ?

B. 25