The critical height for an unsupported vertical cut in cohesive soil is given by _____________

• A. \(H_c=\frac{q-2c cot⁡α}{γ} \)
• B. \(H_c=\frac{4c tan⁡α}{γ} \)
• C. \(H_c=\frac{4 cot⁡α}{γ} \)
• D. \(H_c=\frac{cot⁡α}{γ} \)