$A \rightarrow P$ is a first order reaction. At 300 K this reaction was started with $[A]=0.5 \mathrm{molL}^{-1}$. The rate constant of reaction was $0.125 \mathrm{~min}^{-1}$. The same reaction was started separately with $[\mathrm{A}]=1 \mathrm{molL}^{-1}$ at 300 K. The rate constant (in $\mathrm{min}^{-1}$ ) now is

• A

  $0.25$
• B

  $0.05$
• Correct answer
  C

  $0.125$
• D

  $1.00$

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