• Classification of Irrigation Efficiencies:
• Water Conveyance Efficiency ($\eta_c$): Ratio of water delivered to the farm fields to water diverted from the source canal network: $\eta_c = (W_f / W_d) \times 100$. (True)
• Water Application Efficiency ($\eta_a$): Ratio of water stored in the crop root zone during irrigation to water delivered to the field, directly governed by the irrigation method (surface, sprinkler, drip). (True)
• Economic Efficiency: Evaluates overall economic returns generated per unit cost/volume of irrigation water across the system. (True)
• Conclusion: (A), (B) and (C) are all correct (Option 4).

Correct option: (4) (A), (B) and (C).

• Border Irrigation Method Characteristics:
• High application efficiency: With proper border length, width, and slope matched to soil infiltration, application efficiencies of $70 - 85\%$ are achieved. (Correct)
• Large stream handling: Designed to handle large flow streams, advancing water quickly down the border strip. (Correct)
• Adequate surface drainage: Strip layout allows tailwater to drain cleanly into a collection ditch at the lower end. (Correct)
• (D) Labor requirement: Requires significantly less labor than check basin irrigation because borders are long, continuous, and semi-automated with siphons/spiles. (Incorrect)
• Conclusion: (A), (B) and (C) only (Option 1).

Correct option: (1) (A), (B) and (C) only.