To find the circumference of a circle, we use the formula:
[tex]\[ \text{Circumference} = \pi \times \text{Diameter} \][/tex]
Given the diameter of the circle is [tex]\( 21 \)[/tex] cm and the approximation [tex]\(\pi = \frac{22}{7}\)[/tex]:
[tex]\[ \text{Circumference} = \frac{22}{7} \times 21 \][/tex]
First, notice that [tex]\( 21 \)[/tex] can be simplified in the fraction:
[tex]\[ \frac{22}{7} \times 21 = 22 \times 3 = 66 \][/tex]
Thus, the circumference of the circle is [tex]\( 66 \)[/tex] cm.
Among the given options, the correct answer is:
[tex]\[ \boxed{66 \, \text{cm}} \][/tex]
