Use the vocabulary in the Word Bank to complete the following explanation.

Julia would be observing a. static electricity was caused by her sweater rubbing against her shirt and transferring electrons. she didn't touch anything metal, so that would cancel out b.she most likely didn't rub her sweater against her hair either, so that cancels out c.she also didn't scoot across the carpet while trying to take her sweater off, that cancels out d.so that leaves a.a. is correct.

Answer (d) the universe had cooled enough for atoms to combine, protons and neutrons were too far apart to form nuclei;