Modern-day snakes are believed to evolve from four-legged lizards, but scientists were divided over whether that phase of evolution occurred on land or in the sea; the recent discovery of fossils of a land-dwelling snake with two legs provides new information for the ongoing debate.

A)evolve from four-legged lizards, but scientists were

B)have evolved from four-legged lizards, but scientists are

C)evolve from four-legged lizards, but scientists are

D)have evolved from four-legged lizards, but scientists were

E)be evolving from four-legged lizards, but scientists were

Guys ,

Can you pls explain .

The correct Idiom is - Believe TO BE right?

OA B