7. (6.67 pts) Below are four kernels. Two of them are 1st derivative filters and two of them are 2nd derivative filters. Which of the statements below are true (choose one)? -1 -2 -1 0 0 0 1 2 1 A -1 0 1 -2 02 -1 0 1 B 0 1 1-4 0 1 0 1 0 1 1 1 1 -81 1 1 1 D a. A and Care first derivative filters b. B and D are first derivative filters A and B are first derivative filters d. None of these C