Final answer:
The number of elements in a set is called the cardinal number, and the representation of a set with elements enclosed in curly braces is known as roster form. correct option is A
Step-by-step explanation:
The number of elements in a set is called the cardinal number of the set. So, the correct answer to the first question is a) Cardinal.
The representation of a set that describes the elements enclosed in curly braces is known as roster form. Therefore, the answer to the second question is b) Roster Form. An example of roster form is S = {2, 4, 6, 8}, which lists all the elements of set S within curly braces.