A bar magnet 8 cms long is placed in the magnetic merdian with the N-pole pointing towards geographical north. Two netural points separated by a distance of 6 cms are obtained on the equatorial axis of the magnet. If horizontal component of earth's field \[=3.2\times {{10}^{-5}}T\], then pole strength of magnet is

• A. \[5\,ab-amp\times cm\]
• B. \[10\,ab-amp\times cm\]
• C. \[2.5\,ab-amp\times cm\]
• D. \[20\,ab-amp\times cm\]