The circumference \( c \) of a circle can be calculated using the formula:
\[ c = 2 \pi r \]
where \( r \) is the radius of the circle. Given that the radius \( r \) is 10 inches, we can substitute this value into the formula:
\[ c = 2 \pi (10) = 20 \pi \]
However, the question asks for an expression that represents the value of \( c \) in terms of \( c \) itself, which can be somewhat confusing.
In this case:
- None of the listed options A, B, C, or D correctly represent the relationship for the circumference \( c = 20 \pi \).
Assuming that the question is asking which expression correctly represents a value related to \( c \), the closest are formulas from the given answer choices, but they do not satisfy the true expression for circumference.
If needed, we might reconsider the options based on standard geometric constants and solve accordingly. However, based on what's provided, none of the expressions effectively represent the value \( c \). Would you like me to clarify anything or explore alternative interpretations?