Shane and Karen want to measure the length of a soccer field. Length can be measured in different units such as cm, m ,km , yards etc. The question is asking us to select between two units cm or meters which will be more appropriate to measure the field.
To measure the field a larger unit is required. Meter is a bigger unit than centimeter.Centimeter is not the correct unit to measure the length of soccer field.
Shane and Karen should use meters to measure the soccer field.