The TAL protein appears to bind to specific bases on one strand of a DNA double helix. The shape and charge of the TAL protein probably gives it this specificity. It would then either act on the DNA itself or could complex with other protein(s) to alter DNA.
Work Step by Step
This question is asking you to use your familiarity with the DNA double helix and proteins' binding to it with your knowledge of protein structure and function from earlier chapters. Use this information and your imagination to connect the information in the question to the way in which the TAL protein delicately contacts specific bases in the picture DNA double helix.