You are to choose the 'one' word or phrase that 'best keep the meaning' of the original sentence, if it is substituted for the quotation word or phrase. After years of research Charless Drew devised procedure preserving plasma.

You are to choose the 'one' word or phrase that 'best keep the meaning' of the original sentence, if it is substituted for the quotation word or phrase. After years of research Charless Drew devised procedure preserving plasma.

• transporting (Incorrect)
• saving (Correct)
• reusing (Incorrect)
• labeling (Incorrect)
• None of these (Incorrect)