Which of the following statements is false?

• A
  In chlorine gas,the ratio of $Cl^{35}$ and $Cl^{37}$ is $1 : 3$
• B
  The hydrogen bomb is based on the principle of nuclear fusion
• C
  The atom bomb is based on the principle of nuclear fission
• D
  The penetrating power of a proton is less than that of an electron