Which expression relates half-life T1/2 to decay constant λ?

Which expression relates half-life T1/2 to decay constant λ?

• A. λ = T1/2 / ln(2)
• B. λ = ln(2) × T1/2
• C. λ = ln(2) / T1/2
• D. λ = 1 / (T1/2)^2

Answer: (C)