The correct answer is C) if your vessel's stability is decreasing, the roll period will increase. Explanation: Loading cargo above the vessel's center of gravity will increase the vessel's vertical center of gravity, which decreases the vessel's stability. When stability decreases, the roll period (time for one complete roll from port to starboard and back) will increase. This is because with lower stability, the vessel will take longer to swing back and forth, resulting in a longer roll period. The other options are incorrect because: A) and D) are incorrect because increasing the vertical center of gravity decreases stability, which results in a longer roll period, not a shorter one. B) is incorrect because decreasing stability leads to an increase in roll period, not a decrease.