The correct answer is A) Empty double-bottoms and lower holds, and a heavy deck cargo. This condition could cause a list because an even transverse distribution of weight with empty lower holds and a heavy deck cargo would shift the vessel's center of gravity (G) higher, resulting in a smaller righting arm (GZ) and increased list. The vessel's stability would be reduced, making it more susceptible to listing. The other options are incorrect because: B) A small positive righting arm does not necessarily cause a list, C) Flooding the forepeak would affect the vessel's trim, not necessarily cause a list, and D) Having KG smaller than KM indicates adequate stability, which would not lead to a list.