What is the value of one sided lower cusum?

• A. \(C_i^-=min⁡[0,x_i-(μ_0+K)+C_{i-1}^-]\)
• B. \(C_i^-=max⁡[0,x_i-(μ_0+K)+C_{i-1}^-]\)
• C. \(C_i^-=min⁡[0,(μ_0-K)-x_i+C_{i-1}^-]\)
• D. \(C_i^-=max⁡[0,(μ_0-K)-x_i+C_{i-1}^-]\)