The notch sensitivity q is expressed in terms of fatigue stress concentration factor K_f and theoretical stress concentration factor K_t as

A. $$\frac{{{{\text{K}}_{\text{f}}} + 1}}{{{{\text{K}}_{\text{t}}} + 1}}$$

B. $$\frac{{{{\text{K}}_{\text{f}}} - 1}}{{{{\text{K}}_{\text{t}}} - 1}}$$

C. $$\frac{{{{\text{K}}_{\text{t}}} + 1}}{{{{\text{K}}_{\text{f}}} + 1}}$$

D. $$\frac{{{{\text{K}}_{\text{t}}} - 1}}{{{{\text{K}}_{\text{f}}} - 1}}$$

Answer: Option B