A mutation in a plant's cell changes the gene that codes for a certain protein, and as a result the cell can no longer make the protein. The gene sequences before and after the mutation are shown in the following table. Sequence before the mutationA-T-T -A-T-C-A-T-A

Sequence after the mutationA-T-T-T-A-G-A-T-C- A-T-A

What kind of mutation is shown in the table?

A-frameshift

B-insertion

C-substitution

D-deletion