or each of the following statements indicate whether it is true for a switch $($S$),$ or a router $($R$),$ by writing none, one or both of the letters S and R beside the statement. $($That is$,$ write the letter if the statement is true for the corresponding device.$)$

a$)$ Runs IP:

b$)$ Runs a MAC protocol when connected to an Ethernet segment:

c$)$ Extends the geographic coverage and the number of end systems in the network:

d$)$ Can add non$-$negligible delay to the time to deliver a packet:

e$)$ Can reduce the size of a collision domain:

f$)$ Can reduce the size of a broadcast domain: