Option A - INCORRECT.
Definitely, the price of the extra vehicle-loading service alone will be more than 50% of the price of a regular journey that is why, Southern Seas' management believes such a service would be profitable when put into action.

Option B - INCORRECT.
It is a certain that some car-rental companies would be affected by this new improvement by Southern Seas' management. However, it is impossible for all cruisers to load their cars at the same time, therefore, this will also create room for some car- rentals service provider to still be in business.

Option C - INCORRECT.
Before any business will consider more business idea, definitely the positive influence of such idea would be greater than the risk involve when such idea is implemented. However, Southern Seas management would have considered securing a deal with its fuel suppliers which will grant them a significant discount on the price of extra ship fuel.

Option D - CORRECT.
This option is most adequate to evaluate in this argument. An adequate evaluation of the cost of outfitting the ship's cargo to protect regular vehicles from potential damage caused by the current levels of moisture and salt cost is of topmost importance to Southern Seas' management. Because, customers won't pay that much to have their cars damaged before getting to their destination, also Southern Seas' management would not like to tarnish their image if the customers should complain of their incompetence to secure their cars from potential damage. Therefore, Southern Sea' management should see beyond the profit they are about to make and also place satisfaction of customers at high esteem.

Option E - INCORRECT.
Even if there is a projected decline in cruises to international states in the nearest future, its still of no much concern to Southern Seas, because before then, they would have made enough profit in the business to sustain them for the future unexpected or expected decline in international cruising.