If the diameter of a circle is 10, what is the circumference?

To find the circumference of a circle, we use the formula:

[ C = \pi \times d ]

where ( C ) is the circumference and ( d ) is the diameter of the circle.

In this case, the diameter is given as 10. Now substituting this value into the formula:

[ C = \pi \times 10 ]

This simplifies to:

[ C = 10\pi ]

Thus, the correct answer reflects that the circumference of the circle is equal to ( 10\pi ). This calculation reinforces the relationship between the diameter and the circumference, emphasizing that the circumference is a direct linear function of the diameter, multiplied by π.

This understanding of the formula and how it applies to the problem clearly confirms that the answer is accurate.