The correct option is A Parallell
Phospholipids are the primary molecules found in the plasma membrane, which is a lipid bilayer. Phospolipids have a hydrophilic region called the head and a hydrophobic region called the tail. The hydrophilic region can interact with water due to the presence of a phosphate group which is polar, like water. The membrane is in contact with water on both inner and outer side. The hydrophilic heads arrange automatically on the outer side of bilayer due to polarity and hydrophobic heads are facing each other between bilayer, thus arranging all lipid molecules parallel to each other.