Duke is practicing his spelling in the classroom. duke is going to receive reinforcement after six demonstrations of the target behavior, which is spelling a word correctly.

which of the following statements is true?
a.
duke is on a fixed-interval schedule of reinforcement.
b.
duke is on a variable-interval schedule of reinforcement.
c.
duke is on a fixed-ratio schedule of reinforcement.
d.
duke is on a variable-ratio schedule of reinforcement.