Answer: Option (a) is the correct answer.
Explanation:
A lipid that contains a phosphate group in its molecule is known as a phospholipid.
These are the primary molecules present in a plasma membrane. These tend to contain two hydrophobic fatty acid tails and one hydrophilic head.
Hydrophilic means water loving in nature.
As phosphate group is a polar group due to this the hydrophilic region present in a phospholipid is able to interact with water.
In an amino-alcohol modified phosphate, ester groups, and glycerol, the glycerol is hydrophobic in nature. It also contains two fatty acids and a phosphoric acid which are present as ester. The polar head that mainly consists of phosphate group is hydrophilic and thus, it helps in combining to a water molecules.
Hence, we can conclude that in a phospholipid, amino-alcohol modified phosphate, ester groups, and glycerol are the components which constitute the hydrophilic head.
The apparent topography exhibited by minerals in thin section as a consequence of refractive index.
Aluminum? It is a chemical element with the symbol Al and atomic number 13. It is a silvery-white, soft, non-magnetic and ductile metal in the boron group. By mass, aluminium is the most abundant metal in the Earth's crust and the third most abundant element
The amount of matter in an object is said to be its mass. The SI base unit of mass is kilograms i.e. 
.
The mass of the object = 
(given)
For converting lbs to kg:
So, 
Hence, the mass of 
object in kilograms is 
.
