you have two copper cables of equal length for carrying current. one of them has a single wire of area of cross- section A and other has A/10 each. judge their suitability for for transprting AC and DCa) only single strand for DC and only multiple strand for ACb) either for DC and only multiple strands for ACc) only single strand for AC either for DCd) only single strand for DC either for AC........

The real segment of the A.C. streams on the outside of the wire.
So where a thick wire is required, various meager wires are consolidated to give an identical impact of a thick wire.
Thusly different strands are appropriate for transporting A.C. Correspondingly different strands can likewise be utilized for D.C. this is is the correct answer to to the question.
In case of alternating current (AC) magnetic field woulx often change and inducec current due to self induction would bring an hindrance. So as we have 10 strands then each would cancel the magnetic flux changing and so induced current is reduced to its maximum.
In case of dc no such induction as current is steady. Hence magnetic flux also remains steady.