Switches: select one:
a. operate at the physical layer only
b. connect two or more network segments that use different data link protocols
c. connect two or more network segments that use different network protocols
d. learn addresses by reading the source and destination addresses

b. connect two or more network segments that use different data link protocols

Explanation:

A switch is an analog device that allows to interconnect networks, it is possibly one of the devices with a higher level of scalability. It is important to clarify that a Switch does not only provide connectivity with other networks, nor does it provide connectivity with the Internet, for this purpose a router is necessary.  

answer; i believe the correct answer is (b) by using a multimeter;