Sivaang made the statement "a prime number is always odd”. Dylan replied "2 is a prime number and its an even number”. By which method did Dylan validate/disprove Sivaang's statement?
Contradiction
Dylan's statement counters Sivaang's statement. If Dylan's statement is true, then he has disproved Sivaang's statement by giving a counterexample.
We need to check if Dylan's statement is true. He says, "2 is a prime number and its an even number". This statement is indeed true.
Hence Dylan disproves Sivaang's statement by the giving a counterexample.