You have four interconnected switches all using default RSTP parameters. You are asked to
ensure that S1 becomes the root bridge.
Which configuration will accomplish this task?

A.
{master:0}[edit]
user@S1# show protocols
rstp {
hello-time 2;
interface ge-0/0/1.0 {
cost 1;
}
interface ge-0/0/2.0 {
cost 1;
}

B.
{master:0}[edit]
user@S1# show protocols
rstp {
hello-time 2;
interface ge-0/0/1.0 {
priority 16;
}
interface ge-0/0/2.0 {
priority 16;
}

C.
{master:0}[edit]
user@S1# show protocols
rstp {
bridge-priority 16k;
hello-time 2;
interface ge-0/0/1.0 {
cost 100;
}
interface ge-0/0/2.0 {
cost 100;
}

D.
{master:0}[edit]
user@S1# show protocols
rstp {
bridge-priority 32k;
hello-time 2;
interface ge-0/0/1.0 {
priority 16;
}
interface ge-0/0/2.0 {
priority 16;
}