komal wrote:The widely accepted big bang theory holds that the universe began in an explosive instant ten to twenty billion years ago and has been expandingever Since.

(A) that the universe began in an explosive instant ten to twenty billion years ago and has been expanding
CORRECT TENSES BEGAN IS SIMPLE PAST AND HAS BEEN EXPANDING IS CONTINUOUS
(8) that the universe had begun in an explosive instant ten to twenty billion years ago and had been expanding
INCORRECT: THERE IS ONLY ONE ACTION IN PAST SO SIMPLE PAST IS ENOUGH , AND HAD BEEN EXPANDING INDICATES THE EXPANSION IS STOP RECENTLY IN PAST...ALTERS THE INTENDED MEANING
(C) that the beginning of the universe was an explosive instant ten to twenty billion years ago that has expanded
INCORRECT: beginning of the universe was an explosive instant is wordier than universe began in an explosive instant and is passive ...years has not expanded...meaning altered
(D) the beginning of the universe to have been an explosive instant ten to twenty billion years ago that is expanding
incorrect: the beginning of the universe to have been an explosive instant ten to twenty billion years ago caontains no verb...and use of that makes years not expanding wrng
(E) the universe to have begun in an explosive instant ten to twenty billion years ago and has been expanding
infintive verb phrase is wrng here

OA [spoiler](A)[/spoiler]