In reference to MPLS VPNs, what is a routing protocol context?

A.
Routing protocol contexts are specified in the MPLS RFC as OSPF, BGP, and ISIS.

B.
It is how separate isolated copies of VPN routing instances are created by the IOS.

C.
It is the interface parameters and timers values used to determine which routes are exported.

D.
It is the display keyword used with the show ip route vpnv4 command to display the routing protocol parameters for a particular VRF

Explanation:

1) According to the "Implementing Cisco MPLS" Student Guide (Text Part Number: 97-1154-01) Volume 2, version 1.0, page 8-6.
-Routing context=routing protocol run in one vrf
-Routing contexts were introduced in Cisco IOS software to support the need for separate isolated copies of VPN routing protocols. They can be implemented as separate routing processes (OSPF), similar to traditional Cisco IOS software implementation, or as separate isolated instances of the same routing protocol (EBGP, RIPv2).
2) According to the book "MPLS and VPN Architectures, CCIP Edition "by Jim Guichard , Ivan Pepelnjak.
In chapter 5: To support overlapping VPNs, the routing protocol must be limited to a single VPN routing and forwarding (VRF) table. Each PE router must be configured so that any routing information learned from an interface can be associated with a particular VRF. This is done through the standard routing protocol process and is known as the routing context. A separate routing context is used per VRF. Some routing protocols (for example, RIP) support several instances (or routing contexts) of the same protocol, with each instance running in a different VRF. Other protocols (for example, OSPF) require a separate copy of the routing protocol process for each VRF.