C 
$12
If the cost c is at least $12 then it could be equal to 12, or could also be a cost greater than $12. So, c is greater than or equal to 12, expressed as <span>c $12</span>
If the cost c is at least $12 then it could be equal to 12, or could also be a cost greater than $12. So, c is greater than or equal to 12, expressed as <span>c