Consider the network in Figure. Suppose AS3 and AS2 are running OSPF for their intra-AS routing protocol. Suppose AS1 and AS4 are RIPing for your intra-AS routing protocol. Suppose eBGP and iBGP are used for the intra-AS routing protocol. Initially, assume that there is no physical link between AS2 and AS4. By which protocols do routers 1c, 1d, 3a, and 3c know about the network prefix x?