Objects that conduct electricity poorly are called non-metals.
Electromagnetic waves are waves characterized by oscillating coupled electric and magnetic fields (electromagnetic fields). Because these are waves, they are shown to exhibit wave phenomena such as diffraction, reflection, and transmission, much like other types of waves.
The best description looks like option D
The density is 81.4 g/m3. Before you start plugging numbers into the density formula (D=M/V), you should convert 104 kg to grams, which ends up being 104,000 grams. Then you can plug in the 104,000 grams and 1,278 m3 into the formula. When you divide the mass by the volume, you get a really long decimal, which you can round to 81.4 g/m3, or whatever place your teacher wants you to round to.