How Many Turns Should A $10 - \mathrm { cm }$

Multiple Choice

How many turns should a $10 - \mathrm { cm }$ long ideal solenoid have if it is to generate a $1.5 - \mathrm { mT }$ magnetic field when $1.0 \mathrm {~A}$ of current runs through it? $\left( \mu _ { 0 } = 4 \pi \times 10 ^ { - 7 } \mathrm {~T} \cdot \mathrm { m } / \mathrm { A } \right)$

A) 12
B) 15
C) 1200
D) 120
E) 3200