Answer: A. Alice can pour the water into a graduated cylinder to find the volume
Explanation: If you put water into a graduated cylinder, you get accurate numbers. This helps with the equation because estimating isn't always the best way to go. Putting a ruler in the water wont help because you don't know what number the water started at before the displacement. The thermometer won't work either because that is used for temperature.
Isotonic solution.
Since it has the same salt concentration as the cell the solution is neither hypotonic or hypertonic.
One method I know of is comparing a sample of the rock to other samples which the scientist already knows the age of. I forgot what this method is called but I know it's used by lazy scientists that use other scientist findings like the age of a rock to compare to their own work