The notch sensitivity q is expressed in terms of fatigue stress concentration factor Kf and theoretical stress concentration factor Kt, as

• A. <img src="/_files/images/mechanical-engineering/machine-design/564-99-1.png">
• B. <img src="/_files/images/mechanical-engineering/machine-design/564-99-2.png">
• C. <img src="/_files/images/mechanical-engineering/machine-design/564-99-3.png">
• D. <img src="/_files/images/mechanical-engineering/machine-design/564-99-4.png">