The half-life $\left({\mathrm{T}}_{1/2}\right)$ and the disintegration constant $\left(\mathrm{\lambda }\right)$ of a radioactive substance are related as

• A

  ${\mathrm{\lambda T}}_{1/2}=1$

• B

  ${\mathrm{\lambda T}}_{1/2}=0.693$

• C

  $\frac{{\mathrm{T}}_{1/2}}{\mathrm{\lambda }}=0.693$

• D

  $\frac{\mathrm{\lambda }}{{\mathrm{T}}_{1/2}}=0.693$