Answer
$\int~B\cdot ds = -2.5\times 10^{-6}~T\cdot m$
Work Step by Step
We can find $\int~B\cdot ds$:
$\int~B\cdot ds = \mu_0~i_{enc}$
$\int~B\cdot ds = (4\pi\times 10^{-7}~H/m)(2.0~A-2.0~A-2.0~A)$
$\int~B\cdot ds = (4\pi\times 10^{-7}~H/m)(-2.0~A)$
$\int~B\cdot ds = -2.5\times 10^{-6}~T\cdot m$
