which layer of the OSI model does the Spanning Tree Protocol (STP) operate at?

At which layer of the OSI model does the Spanning Tree Protocol (STP) operate at?

A.
Layer 5

B.
Layer 4

C.
Layer 3

D.
Layer 2

E.
Layer 1

Explanation:
Spanning-Tree Protocol (STP) is a Layer 2 (L2) protocol designed to run on bridges and switches. The
specification for STP is called 802.1d. The main purpose of STP is to ensure that you do not run into a
loop situation when you have redundant paths in your network. Loops are deadly to a network.