The purpose of resistor bank 'R1-R5' in the winch circuit shown in the illustration is to ______________. EL-0102 A. limit armature current in lower and 'series field' current in hoist to obtain required speeds B. divert shunt field current for speed control in both directions of operation C. limit armature current in hoist and 'series field' current in lower to obtain required speeds D. regulate the strength of the brake solenoid 'B1-B2' in both directions of operation