The domain of definition of $f(x) = \frac{\log _2(x+3)}{x^2+3 x+2}$ is :

R – {-1, -2} (-2, ∞) R – {-1, -2, -3} (-3, ∞) – {-1, -2}

(-3, ∞) – {-1, -2}

$x +3 > 0$ $⇒x>-3$ and $x^2+ 3x +2 ≠ 0$ so $(x+1)(x+2)≠ 0$ $x≠-1,-2$ ⇒ Domain = $(-3, ∞) – \{-1, -2\}$ Hence (4) is the correct answer.