The correct option is C 11 inches, 6 inches
Length of blue marker = 15 inches
The length of the red marker is a little less than the blue one.
So, estimated length of red marker = 11 inches
Length of yellow marker = 5 inches
The length of the orange marker is a little more than the yellow one.
So, estimated length of orange marker = 6 inches
Hence, the estimated length of the red and orange marker is 11 inches and 6 inches, respectively.