With no explanation, label text_A→text_B with either "DON'T KNOW", "NO" or "YES".
text_A: After German submarines conducted total and unconditional warfare against American shipping in British waters, the USA formally declared war on Germany in April of 1917. With the U.S. mobilizing for war, President Woodrow Wilson appointed Hoover to head the U.S. Food Administration, which was charged with ensuring the nation's food needs during the war. Hoover had hoped to join the administration in some capacity since at least 1916, and he obtained the position after lobbying several members of Congress and Wilson's confidant, Edward M. House. Earning the appellation of "food czar", Hoover recruited a volunteer force of hundreds of thousands of women and deployed propaganda in movie theaters, schools, and churches. He carefully selected men to assist in the agency leadership—Alonzo Taylor (technical abilities), Robert Taft (political associations), Gifford Pinchot (agricultural influence), and Julius Barnes (business acumen).
text_B: From the passage above, does it sound like the loss of a privately-owned vessel, which carried no weapons or any other war materiel, was the final straw that pushed America into the First World War?
YES.