Which clue points to an inability to keep balance during the Walk and Turn test?

The letter C is associated with the inability to maintain balance during the Walk and Turn test. This test is designed to assess a person's balance and coordination, particularly in the context of potential impairment. Observations made during the test, such as stepping off the line, swaying, or using arms for balance, indicate difficulties with maintaining stability.

In this instance, the letter C serves as a visual representation of such lack of balance, as it resembles a curve which suggests that a person is not moving in a straight line — a key aspect evaluated in the test. Successful completion of the Walk and Turn requires not only following the instructions meticulously but also exhibiting control of one’s body throughout the sequence, which is directly correlated with the ability to maintain balance.