A radioactive sample ${\mathrm{S}}_1$ having the activity ${\mathrm{A}}_1$ has twice the number of nuclei as another sample ${\mathrm{S}}_2$ of activity${\mathrm{A}}_2$. If ${\mathrm{A}}_2=2{\mathrm{A}}_1$, then the ratio of the half-life of ${\mathrm{S}}_1$ to the half-life of ${\mathrm{S}}_2$ is

• Correct answer
  A

  $4$
• B

  $2$
• C

  $0.25$
• D

  $0.75$

Hence, the correct answer is option: 'A'.