Step 1: Understanding the question.
The question is referring to the key characteristics that define National Waterways in India, as outlined in the National Transport Policy Committee (NTPC) of 1980. National waterways must meet specific criteria to be classified as such.
Step 2: Analyzing the options.
(A) Navigability by mechanically propelled vessels: This is a required characteristic, as National Waterways must be navigable by mechanically powered vessels.
(B) 45 m wide channel and minimum 1.5 m depth: Correct — These are physical requirements for National Waterways, ensuring they are wide and deep enough for safe passage of vessels.
(C) Serve the interest of more than one State: This is true because National Waterways typically span multiple states and have a broader national importance.
(D) All of the above: Correct — All the listed options are characteristics of National Waterways as per NTPC 1980.
Step 3: Conclusion.
The correct answer is (D) All of the above, as all the listed criteria are essential characteristics of National Waterways.