The correct option is C
1 and 2
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Long, narrow & very deep vallys located on continental shelves & slope called Submarine Canyons. The Canoyons facing the river mouth are usually long e.g. Congo canyons. these canyons carry various type of ocean deposits. i.e. sands, slits, clays etc.
For instance: Pulicat canyons, Pondicherry canyons, Krishna canyons are present on east coast of India