Answer:
d. shaping
Step-by-step explanation:
Shaping: In psychology, the term shaping is defined as a process of getting a desired final behavior by reinforcing sequentially a closer and closer approximation. This is one of the major parts of the applied behavior analysis. It starts with the process of identifying whether a person wants to learn or change a particular behavior.
Example: A child starts his study from the first standard, then gradually twelfth, then bachelors, etc, through reinforcement.
By reinforcing progressively better attempts at writing letters, Mrs. Martin is using a shaping technique.