The boiling points of methanol,water,and dimethyl ether are respectively $65\,^{\circ}C$,$100\,^{\circ}C$,and $-24.8\,^{\circ}C$ (note: dimethyl ether is a gas at room temperature). Which of the following best explains these wide variations in boiling point $(b.p.)$?

• A
  The molecular mass increases from water $(18)$ to methanol $(32)$ to dimethyl ether $(46)$.
• B
  The extent of $H$-bonding decreases from water to methanol,while it is absent in dimethyl ether.
• C
  The extent of intramolecular $H$-bonding decreases from dimethyl ether to methanol to water.
• D
  The density of water is $1.00\, g\, mL^{-1}$,methanol is $0.7914\, g\, mL^{-1}$,and that of dimethyl ether is $0.7137\, g\, mL^{-1}$.