Consider the network shown below. Suppose AS$3$ and AS$2$ are running

OSPF for their intra$-$AS routing protocol. Suppose AS$1$ and AS$4$ are running$$RIP for their intra$-$AS routing protocol. Suppose eBGP and iBGP are used$$for the inter$-$AS routing protocol. Initially suppose there is no physical link$$between AS$2$ and AS$4.$

a$.$ Router $3$c learns about prefix x from which routing protocol: OSPF, RIP,

eBGP, or iBGP?

b$.$ Router $3$a learns about x from which routing protocol?

c$.$ Router $1$c learns about x from which routing protocol?

d$.$ Router $1$d learns about x from which routing protocol?