Mr. reese conducted a concept lesson in math and assigned a challenging task. he expected some of his students to grasp the concept and complete the task with moderate effort, but he knew other students would not. he monitored their progress, stopping to ask prompting questions or drop hints to students connect prior learning with this new concept. mr. reese was providing:
a. cognitive constructivism
b. social negotiation
c. scaffolding
d. spiral curriculum

Scaffolding

Explanation:

Scaffolding is a term that is proposed by Vygotsky. Zone of proximal distance and the concept of Scaffolding are a similar method that is used in teaching methods.

This is the method through which a student gets more information more rapidly than a traditional method. This method is beneficial only when you implement it accurately. On the other hand, if it is not used correctly, it hinders the ability of a student.  

Thus Mr. Reese used the scaffolding method in his teaching. He monitored students' progress, stopping to ask prompting questions and drop the hints to help the students.

its d i know cause i've been googling it