Assertion(A) : Coliform bacteria are organisms that are present in the environment and in the faeces of all warm blooded animals and humans.
Reason(R) : Most coliform bacteria do not cause diseases.
A) both A and R are true and R is the correct explanation of A
B) both A and R are true but R is not the correct explanation of A
C) A is true but R is false
D) A is false but R is true