Match the following:

Metal	Ore
$1$. Sodium	$a$. Barite
$2$. Potassium	$b$. Carnallite
$3$. Barium	$c$. Beryl
$4$. Beryllium	$d$. Chile saltpetre

(C) The correct matches are:
$1$. Sodium $(Na)$ is found in Chile saltpetre $(NaNO_3)$.
$2$. Potassium $(K)$ is found in Carnallite $(KCl \cdot MgCl_2 \cdot 6H_2O)$.
$3$. Barium $(Ba)$ is found in Barite $(BaSO_4)$.
$4$. Beryllium $(Be)$ is found in Beryl $(Be_3Al_2Si_6O_{18})$.
Therefore, the correct sequence is $1-d, 2-b, 3-a, 4-c$.