A current-carrying wire is known to produce magnetic lines offorce around the conducting straight wire. thedirection ofthe lines of force may be described by:

• A. left-hand thumb rule for up-current and right-hand thumb rule for down-current
• B. right-hand thumb rule for up-current and left-hand thumb rule for down current
• C. right-hand thumb rule for both up and down currents
• D. left-hand thumb rule for both up and down currents