some tools have graduations to show multiple measurements. for example, a ruler may have graduations for both millimeters and centimeters. when measuring the length of an earthworm, which graduations would allow for the most accurate measurement?
a. millimeters
b. centimeters
c. decimeters
d. meters

Since earthworms vary in size, the answer to this question could be either millimeters or centimeters. Thankfully, most rulers with centimeters also have graduations of millimeters, thereby making the measurement even more accurate. For example the average earthworm is twelve centimeters, but what if it's three marks past the twelve? The correct answer would be: 12 centimeters plus 3 millimeters or 12.3 centimeters.

The answer is option a.