AC has real economic and technical advantages: economical production (A-true), can be easily stepped up/down using transformers (B-true), and can be transmitted economically over long distances at high voltage with low current, reducing $I^2R$ losses (C-true).

However, AC is NOT necessarily less dangerous than DC — in fact, AC can cause sustained muscle contraction and is often considered comparably or more dangerous at the same voltage/current levels.

Answer: (D) ac is less dangerous