Which of the following expression depicts Barkhausen criteria?

• A. A‚âà√≠‚Äö√¢¬ß = 1
• B. A‚âà√≠‚Äö√¢¬ß = 0
• C. A‚âà√≠‚Äö√¢¬ß < 1 < A‚âà√≠‚Äö√¢¬ß
• D. A‚âà√≠‚Äö√¢¬ß < 1