The correct answer is A) be subject to severe racking stresses. A vessel with a large GM (metacentric height) will have a short, stiff roll period, which makes it more susceptible to racking stresses. Racking stresses are caused by the rapid changes in direction during the vessel's roll, leading to excessive structural loads. This can cause damage to the hull and superstructure. In contrast, a vessel with a smaller GM will have a longer, more gentle roll period, which reduces racking stresses. The other options are incorrect because: B) a vessel with a large GM will have a small amplitude of roll, not a large one; C) a vessel with a large GM is less likely to ship water on deck due to its stiffer roll; and D) a large GM does not make the vessel less likely to have cargo shift, as other factors like the vessel's stability and cargo securing arrangements are more important.