Answer: Substitution
Step-by-step explanation:
The substitution can be defined as the change in the single base pair of the DNA which results in the change in the protein formed.
The mutation that can be seen here is substitution which is caused because the base pair T is replaced by A in the given sequence.
This will result in the change in the protein formed. This type of substitution mutation can form faulty protein or might not change the protein formed as the newly formed code can also result in the same protein which was formed earlier.