If the clearance ratio for a reciprocating air compressor is 'K', then its volumetric efficiency is given by

• A. - k + k (p₁/p₂)1/n
• B. + k - k (p₂/p₁)1/n
• C. - k + k (p₁/p₂) n- 1/n
• D. + k - k (p₂/p₁) n-1/n