Final answer:
The protein that is a double-ring tetradecamer, cylinder-shaped chaperonin responsible for isolating polypeptides to facilitate folding is GroEL, which is a member of the Hsp60 family.
Step-by-step explanation:
The protein described in the question is a double-ring tetradecamer, cylinder-shaped chaperonin that isolates the polypeptide allowing it to fold correctly. The correct answer among the options provided is A) GroEL. This molecule is part of a complex with GroES and together they are essential in assisting protein folding within the cell. GroEL is classified as a Hsp60 family member and helps to prevent aggregation and misfolding of the polypeptide chains, particularly under stressful conditions such as increased temperature (heat shock), changes in pH, or the presence of certain chemicals. The mention of the Hsp70 protein relates to a different chaperone system that also aids in protein folding and translocation, especially across the mitochondrial membrane.