Nancy and hiyang are training for a race. they entered some of their training notes in a chart. which information should be added to the chart in order find out who ran a greater distance? a: the time spent running each day b: the reference point used each day c: the units used to measure distance each day d: the location used by the runners each day

The correct option is C.
In order to find out the person who ran the greater distance, the information that documents the distance that each person ran is needed and this data must have the appropriate units for the distance recorded. The units will helped in determining the actual distance that each person covered. For instance, there is a great difference between one mile and one kilometer, thus it will be wrong to write just one as distanced covered without adding any unit to it.

The answer is option c.