Reverse Cold Chain is used for -: (A) Carrying stool samples of polio patiens from a PHC to the lab, (B) Transpoing outdated vaccines from PHC to district hospital, (C) Transpoing vaccines to lab. to check its potency, (D) Transpoing vaccine form camps to sub - centre
Answer is A. Ans. is 'a' i.e., Carrying stool samples of polio patients from MC to lab "Reverse cold chain" is for transpo of ble poliovirus in stool to an investigation centre.