Effective rate of protection for domestic country is calculated by

A. $${\text{e}} = \frac{{{\text{t}} - {\text{ar}}}}{{1 + {\text{a}}}}$$

B. $${\text{e}} = \frac{{1 + {\text{a}}}}{{{\text{t}} - {\text{ar}}}}$$

C. $${\text{e}} = \frac{{{\text{t}} - {\text{ar}}}}{{1 - {\text{a}}}}$$

D. $${\text{e}} = \frac{{1 - {\text{a}}}}{{{\text{t}} - {\text{ar}}}}$$

Answer: Option C