Answer: (e) is made of open structured, hexagonal crystal.
Explanation:(1) ice has hexagonal 3-dimentional crystal structure.
(2) this hexagonal crystal structure are formed due to-
(a) intermolecular hydrogen bonding.
(3) when ice melts, hydrogen bond breaks and some empty spaces are left behind which water molecules takes place.
(4) water molecule(liquid) are more closely packed than the molecules in ice so the ice has lower density than water.