Which one among the following is the correct order of west flowing rivers in terms of decreasing size of their river basins ?

1. ANarmada—Tapi — Sabarmati — Mahi
2. BTapi —Narmada—Mahi—Sabarmati
3. CSabarmati—Narmada—Tapi — Mahi
4. DNarmada—Tapi — Mahi — Sabarmati