Answer:
a. hammering all of the nails in while Sam watches
Explanation:
Scaffolding: In psychology, the term scaffolding is defined as an "instrumental technique" whereby a specific teacher gives individualized support to his or her student or learner via incrementally improving the student's or learner's capability to form prior knowledge. The phenomenon of scaffolding can be utilized in various areas and throughout different grade and age levels.
The concept of scaffolding was proposed by Lev Vygotsky and is also referred to as “Vygotsky scaffolding”.