We cannot conclude any of A, B, C.
$\mathrm{G}$ may have cycle and still may have unique minimum spanning tree. $\mathrm{G}$ may have any number of cycles and still may have unique minimum spanning tree. For instance, if ALL edge weights are distinct, we can only have unique MST.
If $\mathrm{G}$ does not have distinct weights then it does not imply that we have more than one minimum spanning tree.