$\begin{array}{1 1} (a)\;\text{Arabian sea on one side and Bay of Bengal on the other side } \\ (b)\; \text{Indian ocean on one side and Bay of Bengal on the other side } \\ (c)\; \text{Arabian sea, Bay of Bengal on one side and Himalayas on the other side } \\ (d)\; \text{Arabian sea, Bay of Bengal and Indian ocean on one side and Himalayas on the other side } \end{array}$