(d)
Since, $(3,\ 3),\ (6,\ 6),\ (9,\ 9),\ (12,\ 12) \in R \Rightarrow R$ is reflexive.
Now, $(6,\ 12) \in R$ but $(12,\ 6) \notin R \Rightarrow R$ is not symmetric.
Also, $(3,\ 6),\ (6,\ 12) \in R \Rightarrow (3,\ 12) \in R$
$\Rightarrow R$ is transitive.