Please help me #4

[Danielle]

D is definitely the correct answer. The confusion here is that 'it claims' gets between what and the verb you must choose. Just use trim the fat technique and you can see that 'is' is correct.

Ex.

Electronics company has unveiled what...to be the world's smallest (doesn't make sense)

Electronics company has unveiled what...is the world's smallest (correct)

D is the best choice because it also is most concise, with correct verb tenses and active voice.

[nobody29]

Thank you very much Danielle,
you must be a really kind person.

I thougt "What (it claims to be blah blah~~)"
intead of "What (it claims) to be blah blah~~"
cuz I couldn't find ",".

But after seeing your comment, I think it becomes more clear.

Thank you.

[Danielle]

You're welcome! I'd like to encourage you the freely use that "trim the fat" technique, because there are lots of times on the GMAT where two parts you need to analyze for parallelism or agreement are separated by a bunch of phrases or extraneous words.