Algo doubt

Question

Assume f(n) and g(n)  are two functions such that f (n)=O(g(n))

which of the following always hold

F(n) = O (f(n)²)

F(n) = Ω (f(n)²)

G(n) = O (f(n)²)

G(n) = Ω (g(n))

Comments

but you can not say that,

g(n) = O (f(n)2)  Never hold true.

sometimes it may be true(depending on f(n) and g(n))

---

Question is following always hold .

Nowhere i said never hold true. Counterexample are given to show not hold not for hold. Hope you get it

---

I think we have to consider all possible cases for something to always hold true. Therefore D should be correct.