If it is picking out a sentence in the paragraph, I would say "Researchers have been able to use this inherent intelligence to teach Koko sign language.
I suppose the last sentence ("Hopefully...") is underlined. In my opinion, the correct answer is C. <span>It is an opinion that reflects the journalist’s bias regarding the transportation strike. The journalist is not being neutral in this sentence. He/she judges that the strike is unnecessary, which is definitely bias - the transportation workers definitely don't think it is unnecessary, and with this sentence, the journalist takes a side, which is not allowed in good journalism.</span>
