Write the next sentence in the following story.

How to get rid of drain flies
Identify the problem areas.
Examine all the drains in your home and any area inside or outside the home that has standing water. Any area with multiple drain flies is likely a problem.

Pick from:
(A). Drain flies can also spread the runoff from other sources into other areas. If you have a bathroom sink, shower, and toilet, it may be a good idea to remove drain flies by dropping pebbles.;
(B). Look for schools of worms, fly droppings, or particularly dark, musty smells that indicate pollution or poor drainage. Keep in mind here that when it comes to drain flies, most people do not agree with the choice.;
(C). Water that collects in the walls, cracks, or crevices should be addressed. Water with drain flies can include : Cracks not moving in pipes wall that does not have sewer lines water that flows through holes holes in closets or under stairs Dissolve drain flies.;
(D). Luckily, drain flies do not stray far from the place they have chosen to make their home, so it is rare for a drain fly infestation to spread to all areas of the house. This is especially true if you catch the problem early.;. The answer should be
(D).