What happens/is likely to happen if the atoms within an element have full valence shells?

Question

$\begin{array}{1 1} \text{a.They are likely to bond with other elements more easily.} \\ \text{b. They are unlikely to bond with other elements.} \\ \text{c. They will be labelled as "unstable".} \\ \text{d. They will explode.} \end{array} $