Electromagnetic field (EMF) strength around cables is primarily influenced by current, not voltage. In a single-phase system, the live and neutral conductors are separated, creating a larger magnetic loop area. This produces stronger stray EMF when current increases.
In a balanced three-phase system, the magnetic fields from the three conductors largely cancel each other out, resulting in much lower net EMF, even at higher currents.
Therefore, the correct statement is that increasing current in single-phase cables produces higher EMF compared to three-phase cables. Options B, C, and D incorrectly link EMF to voltage or incorrect current behavior.
References: IEEE Std 141 (Red Book - Power Distribution), IEC 61000-5-7 (EMF mitigation guidelines), ANSI/TIA-942-B §6.6.