Classify the following teaching strategies as pre-instructional, co-instructional, or post-instructional: Defining what the student will learn, providing students with enough information and materials to complete their general understanding of the subject, and students already having a general vision of the subject.
a. Pre-instructional
b. Co-instructional
c. Post-instructional

a. a, b, c
b. b, c, a
c. a, c, b