SmarpanGamt wrote:The relationship between cell phone use and the incidence of brain tumors is still unclear, this is because some studies show a causal relationship while others do not.
is still unclear, this is because some studies show
is still unclear; some studies show
are still unclear because some studies show
is still unclear because: some studies show
is still unclear; the reason is that some studies show
The first option solves the problem of comma splice by introduction of conjuction. Please explain Y this choice is incorrect. Also explain your bet.
I am happy to help.
Firstly, let us look at how we can connect 2 independent sentences - i.e., sentences that have an independent noun + an independent verb and that can be read on their own. There are
2 main ways to do this grammatically -
1.
Semi Colon[;]/ Dash[-]/ Colon[:]/ Full stop[.] (Note that the difference in their semantic usage, i.e.,
when one form of the punctuation is more appropriate than the other is something that is not tested on the GMAT) -
John eats (sentence 1);
Sam drinks (sentence 2)
2.
Comma [optional]+ Conjunction (and, or, but, because, since, although, etc.) -
John eats (sentence 1) and/or/but/although..
Sam drinks (sentence 2).
Additionally, we cannot connect 2 independent sentences using a simple comma - this creates a
Run-on sentence. This is exactly what option A is guilty of when it introduces the clause starting with "
this is" - if this clause weren't there, and the sentence read "The relationship between cell phone use and the incidence of brain tumors is still unclear, because some studies show a causal relationship while others do not. ", then option A would have been correct, albeit a bit wordy due to the presence of a redundant "
because of".
Let us go through the other options -
B. is still unclear; some studies show - perfect and concise. Follows rule #1 grammatically
C.
are still unclear because some studies show - 'the relationship' is singular
D. is still unclear
because: some studies show - After "
because", we need a complete clause before the colon
E. is still unclear;
the reason is that some studies show - Unnecessarily wordy and redundant, since the semi-colon basically gives a reason (in this construction) as to why the relationship is unclear
Hence,
B is the best answer.
