Vygotsky defines as the process of less as the learner improves at a given task.

Scaffolding                      

Explanation:

The term scaffolding is defined by Lev Vygotsky who was a Soviet psychologist. According to him, scaffolding is a part of the zone of proximal development or ZPD.

Scaffolding: It refers to an instructional method that includes a teacher or a guide to explain the process of problem-solving to their students, along with that they also explain the steps as they move ahead. A point will come where the teacher would fade away to explain and asks the students to work themselves independently and assistance is given when required and requested by the students.

i would say b. research typically uses a variety of sources

c it has to be i googled it