<prompt> The risk of cold chain failure is greatest at:-Regional levelDistrict LevelPHC levelSubcentre village level  <response>: The risk of cold chain failure is greatest at Subcentre village level. Cold chain maintainence occurs at 5 major levels in India 1.Regional State - WIC, WIF 2. District - ILR , DF 3. PHC - ILR , DF small in size 4. Sub center - vaccine carrier 5. Village - Ice pack All vaccine Transpo in India at Temp. of 2 to 8degC 