Distance, one of the four characteristics of mapping rules, refers to _____.
a) the use of ordered numbers such that two is less than three but greater than one
b) the use of numbers used to group or sort responses when no order to the numbers exists
c) the use of a series of numbers in which each number is an equal distance from the next
d) the use of a series of numbers with a unique origin indicated by the number zero
e) the use of a number that is not used again