tough sc from gmat prep

[750plus]

this might be easier to understand if we look at an example for which there's a word that means 'not X' (so that we can take away the source of confusion).

consider: if you do not have hair, then you are bald.

if someone writes
All of these people do not have hair
then it is impossible to tell whether the intended meaning is
1/ all of them are bald,
2/ not all of them have hair (= at least one of them is bald).

Yes, this made it super easy. I am fine now.

Thanks

Warm Regards

[RonPurewal]

sure.

[aflaamM589]

Hello Ron,
Can you help understand issues in other choices?
for instance,
is there any other problem with C apart from having the same error as in A?
Is a requirement placed incorrectly in D?
Is tense an issue in CDE? We are talking about fact so present perfect tense (has/have past participle) just not cut whereas tense in A and B is perfect for this job.
Can you validate my analysis and/or add yours.
Thanks in anticipation.
Have a nice day

[RonPurewal]

i don't think this problem actually comes from the GMAT Prep software. (the sentence is badly written -- "even though" doesn't make sense. a good writer would write "even if")

if this problem IS actually in the GMAT Prep software, please post a screenshot directly from the software. otherwise we cannot continue to discuss this problem.

thank you.