Which of the following first order formulae is logically valid?

Question

Which of the following first order formulae is logically valid? Here $α(x)$ is a first order formula with $x$ as a free variable, and $β$ is a first order formula with no free variable.

1. $[β → (\exists x, α(x))] → [\forall x, β → α(x)]$
2. $[\exists x, β → α(x)] → [β → (\forall x, α(x))]$
3. $[(\exists x, α(x)) → β] → [\forall x, α(x) → β]$
4. $[(\forall x, α(x)) → β] → [\forall x, α(x) → β]$

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My attempt :

1. If any is true then all need not be true.
2. If any is true then all need not be true.
3. If any is true then all need not be true.
4. Seems true, since only $x$ is bounded variable in $\alpha$.Actually LHS is equivalent(bi-conditional) to RHS ; so, implecation is also true.

Can you explain with the help of example(s) for each option, please?