The latest reports indicate that the percentage is aprox. 67%. This rounds up to 70%
The answer is D.
Some of the cold water flows southward along the east coast of North America, inshore of the Gulf Stream, as far as Cape Hatteras. The remainder curves toward the east and flows along the northern<span> edge of the North Atlantic and Northeast Drift Currents, gradually merging with them.</span>
The variable is the group that was given caffine, because thats what the doctors manipulated. They possibly altered the natural memory of the participants by giving them caffine. A more specific variable could be how much caffine each participant is given and what time are they given it.
