Correct option is C
The correct answer is (c) Both (A) and (R) are true but (R) is not the correct explanation of (A).
Explanation:
Assertion (A): Fake news spread in world has become a serious problem → True, because fake news causes misinformation, confusion, and societal harm.
Reason (R): The internet is source of all fake news → Partly true, since the internet is a major source of fake news, though not the only one (it also spreads through word of mouth, print, and broadcast media).
However, (R) does not directly explain why fake news has become a serious problem — it merely states one medium of spread.
Hence, both (A) and (R) are true, but (R) is not the correct explanation of (A).