If A is a subset of B and B is a subset of C, then cardinality of A U B U C is equal to ____________
(a) Cardinality of C
(b) Cardinality of B
(c) Cardinality of A
(d) None of the mentioned
The question was asked in an international level competition.
The question is from Cardinality of Sets topic in portion Basic Structures: Sets, Functions, Sequences, Sums and Matrices of Discrete Mathematics