Unlike other kinds of liquids, volatile liquids
a. evaporate rapidly at a relatively low temperature.
b. ignite readily at a relatively low temperature.
c. flow rapidly at a relatively low temperature.
d. freeze readily at a relatively high temperature.

A
(Volatile liquids, liquids with a high vapor pressure or low boiling point) 

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.