What is the SI unit for density of an object

Which statement best describes copper? a. it has a low resistance and prevents charges from moving freely. b it has a high resistance and allows charges to move freely. c. it has a high resistance and prevents charges from moving freely. d. it has a low resistance and allows charges to move freely

If anyone who can me with this hw? i would really appreciate it

Another word for electromagnetic energy is a. heat b. force c. matter d. radiation