Which equation is used to calculate the half-life of the first-order reaction below?
A) t₁/₂ = ln(k / 2)
B) t₁/₂ = (ln(2)) / k
C) t₁/₂ = ln([A] / k)
D) t₁/₂ = 2 * ln(k)
E) t₁/₂ = (ln k) / [A]