Which of the following statement is a tautology?

From De Morgan's Law,

$~ \left(p ∨ q\right) = ~ p ∧ ~ q$

$p \to q = ~ \left(p ∧ ~ q\right)$

\left(~ p ∧ q\right) \to \left(p ∨ q\right)

$= ~ \left\{\left(~ p ∧ q\right) ∧ \left(~ p ∧ ~ q\right)\right\}$

$= ~ \left\{~ p ∧ f\right\}</p><p>$= ~ \left\{f\right\}$= t$, where $f$ is contradiction and $t$ is tautology.