MPLS L3VPN Option C

1- why MPLS command is running b/w ASBR ? i think LDP is distributing lable then how only mpls command distribute lable b/w ASBRs?

for BGP label distribution MPLS is command is pre requisite?

2- which lable(Which values in lable BGP,LDP?)  is attached through apply label  commands ? if LDP is distributed lable but how as ldp is not b/w ASBRs?

3- as in option C we are establishing end to end tunnel then its means that need to carry same RT value through out the path from one PE  to other PE in VPN lablel.

Thanks