hello, ive been doing some sample practice questions on various sites that give them for free and i thought some of their answers were wrong, but i need confirmation from some of you

1. describe link-state routing protocols.
a. common view of entire topology
b. exchange routing tables with neighbors
c. calculate shortest path
d. event triggered updates
e. periodic updates..
they said the correct answers are b, c, d. I thought the correct ones were a, c, d...My reasoning for this is that link-state protocols have a very good understanding of the entire networking topology. Also i think that they send routing updates not only to their neighbors but to all routers that they can reach
2. would mac addresses be associated with serial interfaces? eg. would a show arp on a router display listings for a mac address to serial interface mapping ?
i believe mac addresses are only associated with ethernet interfaces. am i correct?
3. admin wants to config switch over telnet session from outside the lan. which would be required for this to be possible
a. switch has to have ip/subnet mask/default gateway configured
b. switch has to be connected to router over vlan trunk
c. switch must be reachable through a port connected to its management vlan
d. switch console port must be connected to ethernet LAN
e. switch management vlan must be created and have a membership of at least one switch port.
f. switch must be configured as SMTP server.
they said the answers were A, E... However, i think the answers are A, C.. E to me doesnt make sense because you dont need to create the management vlan because its already created by default[vlan1].. Any opinions on this one?
4. what are benefits of vlans
a. increases # of broadcast domains
b. decreate # of broadcast domains
c. increase # of collision domains
d. decrease # of collision domains
it says only pick one answer. I know that vlans do both a and c .. but if they say just pick 1 answer, which one is more Correct to pick ?
5. how can u connect a pc directly to a router
a. conect pc's etheret port ro routers ethernet port using crossover cable
b. conenct pc's com port 2 routers console port using crossover cable
it says answer is a .. why cant u use a converter that plugs into the computers serial port on one side and attaches to the routers console port on the other side.. isnt that correct as well ?
also ive heard of some people refer to crossover cables as rollover cables.. are these terms interchangable or are there differences between the two.
Thanks