A Long Solenoid Is Wound Around a Silver Core $\chi$ _m = -2

Multiple Choice

A long solenoid is wound around a silver core ( $\chi$ _m = -2.6 $\times$ 10^-5) and carries a current.If the core is removed while the current is held constant,the magnetic field inside the solenoid

A) remains constant.
B) increases by approximately 0.003%.
C) decreases by approximately 0.003%.
D) increases by approximately 0.007%.
E) decreases by approximately 0.006%.