Explanation : Let L1 = an bn⇒ CFL
L2 = Σ* ⇒ Regular
L1 ∪ L2 = (an bn) ∪ Σ* = Σ* ⇒ Regular
Since L1 ∪ L2 is regular but L1 is not regular, Hence statement I is false.
Regular language is not closed under infinite union.
Hence, statement-II is also false.
∴ Neither I nor II is true.