What is the purpose of the modal verb in the sentence 'You must not use the lifts in the event of a fire Is it - Giving advise, Showing ability, showing permission or showing compulsion

Which is the main claim in "say no to library cuts"? a. the most important effects of the library cuts will not be limited to children, senior citizens, or other specific groups. b. the budget cuts at the library also mean the end of the children's story hour. c. according to library director sarah tomlinson, whom i interviewed on may 6, the budget cuts will force the library to discontinue many popular programs and services. d. the funding of the public library should be protected because the library offers important programs and services that benefit the whole community.