A solenoid is 1.5 m long and its inner diameter is 4.0 cm . It has three layers of windings of 1000 turns each and carries a current of 2.0 amperes. The magnetic flux for a cross-section of the solenoid is nearly
A. `2.5 xx 10^(-7) "weber"`
B. `6.31 xx 10^(-6) "weber"`
C. `5.2 xx 10^(-5)"weber"`
D. `4.1 xx 10^(-5) "weber"`