The correct answer is D) Prevent overcarriage by block stowage. The fundamental objective of cargo stowage is to ensure the stability and safety of the vessel by properly distributing the weight of the cargo. One way to achieve this is through block stowage, which involves stowing cargo in a compact, uniform manner to prevent shifting or overcarriage during the voyage. This helps maintain the vessel's trim and stability, which is crucial for safe navigation and cargo handling. The other options are incorrect because they do not directly address the primary objective of cargo stowage. Option A is too specific, while options B and C, while important considerations, are not the fundamental objective.