We know that magnetic field lines tend to form a closed loop! we also know that light is a electromagnetic wave so it has an associated magnetic field with it, at any instant $t$ the $ B = B_{0} \sin (\omega t - kx + \phi) $, I cannot find any way how this field might follow the above property!
if it doesn't, then please explain the reason and if it does or I am asking something trivial, be kind enough to answer
