Solve the differential equation:
[ {dr}/{dt} = 180t i + (180t - 16t²) j ]
with the initial condition r(0) = 100j .
a) r(t) = (90t²)i + (180t² - {16}{3}t³)j
b) r(t) = (90t²)i + (90t² - {16}{3}t³)j
c) r(t) = (90t²)i + (180t³ - {16}{3}t⁴)j
d) r(t) = (90t)i + (90t² - {16}{3}t³)j
