Brent@GMATPrepNow wrote:

hemant_rajput wrote:Since the start of space age, more and more littering has occurred in orbits near Earth, often because the intentional discarding of lens caps, packing material , fuel tanks and payload covers.

a) more and more littering has occurred in orbits near Earth, often because
b) orbits near Earth have become more and more littered , often from
c) orbits near Earth became littered more and more, often resulting from
d) there have been more and more littering of orbits near Earth, often because of
e) there had been littering more and more of orbits near Earth, often with

[spoiler]OA:B[/spoiler]

The sentence begins with "Since the start of space age." This tells us that the problem has occurred at an indefinite time in the past, and may continue into the present and future. This requires us to use the present perfect tense (i.e., has occurred, have occurred, have become, etc. ).

Aside: we have a free video on perfect tenses: https://www.gmatprepnow.com/module/gmat- ... on?id=1178

Since we need the past perfect tense here, we can ELIMINATE C and E
c) orbits near Earth became littered more and more, often resulting from
e) there had been littering more and more of orbits near Earth, often with

Now we'll examine the remaining options.
a) more and more littering has occurred in orbits near Earth, often because
In this context, the part following because should be a clause that explains why more littering has occurred.
However, the part after because reads, " the intentional discarding of lens caps, packing material , fuel tanks and payload covers."
There's no verb here, so it's not a clause.
ELIMINATE A

b) orbits near Earth have become more and more littered , often from
Looks good - keep it for now.

d) there have been more and more littering of orbits near Earth, often because of
Littering is singular but have been is plural.
ELIMINATE D

Answer: B

Cheers,
Brent