Need help. brainliy to the first person that answers is right telling why

Which of the following statements is true about germany's use of u-boats?

Which of the following best describes the 1957 events at central high school in little rock, arkansas? -governor faubus resisted the school’s integration with national guard troops, and president eisenhower sent federal troops to enforce integration.-under governor faubus, little rock police first fought, then enforced, the order to integrate the school.-president eisenhower sent national guard troops to resist the school’s integration, but governor faubus obtained a court order to dismiss them.-president eisenhower and governor faubus worked together to make the integration process run as smoothly as possible.

What is the line drawn on a production possibilities graph called?