Rain showers have continued over a particular area for several days as a consequence of a stationary front. Option B is correct.
A stationary front is a pair of air masses, neither of which is strong enough to replace the other.
A wide range of weather can be found along a stationary front, especially, prolonged precipitation, and storm trains are found there. When there is a lot of water vapor in the warmer air mass, great amounts of rain or freezing rain can take place.