I think the answer is D. by determining if goals are actually worthwhile.
" Ablockade is an effort to cut off supplies, war material or communications from a particular area by force, either in part or totally. A blockade should not be confused with an embargo or sanctions, which are legal barriers to trade. It is also distinct from a siege in that a blockade is usually directed at an entire country or region, rather than a fortress or city. While most blockades historically took place at sea, blockade is still used on land to prevent someone coming into a certain area."
The area around present-day Cairo, especially Memphis, which was the old capital of Egypt, had long been a focal point of Ancient Egypt due to its strategic location just upstream from the Nile Delta.
On January 31, 1917, Germany, determined to win its war of attrition against the Allies, announced it would resume unrestricted warfare in war-zone waters. Three days later, the United States broke diplomatic relations with Germany, and just hours after that the American ship Housatonic was sunk by a German U-boat.
