Consider the sets below. u {x|x is any color} a {x|x is a color of the rainbow} r {x|x is red, yellow, or blue} is r ⊂ a? a. yes, because all the elements of set a are in set r b. yes, because all the elements of set r are in set a c. no, because each element in set a is not represented in set r d. no, because each element in set r is not represented in set a