Option 1: (A), (B) and (C) only -> Incorrect because river terraces are primarily erosional features formed when rivers cut down through previous floodplains, not purely depositional.
Option 2: (A), (B) and (D) only -> Incorrect because river terraces are erosional features and this excludes deltas which are major depositional landforms.
Option 3: (A), (C) and (D) only -> Correctly identifies all three major depositional landforms: alluvial fans (sediment deposits in fan shape), deltas (river mouth deposits), and flood plains (riverbank deposits during floods).
Option 4: (B), (C) and (D) only -> Incorrect because it includes river terraces which are erosional features, not depositional landforms.
Hence, Option 3: (A), (C) and (D) only -> Alluvial fans, deltas, and flood plains are all formed by sediment deposition processes. River terraces are primarily erosional features created when rivers incise downward through existing floodplains, leaving elevated flat surfaces behind -> correct