Questions about Default route

Scenario:

I have a pc (192.168.8.2) connected to a switch and then connected to a router A (fa0/0 192.168.8.1).

routerA Serial 0/1 (192.168.5.1)
is connected to a WAN serial 0/1 (192.168.5.2)of RouterB

RouterB has LAN which is (fa0/0 192.168.4.0)

RouterB Is connected to a WAN (serial 0/0 192.168.3.1) to
RouterC (192.168.3.2)

* RouterB Is statistically connected and can ping to A and C
* RouterC is statistically connected and can ping to B

So what i did, At router A
I typed the default route which is

ip_route_0.0.0.0_0.0.0.0_serial 0/0

and then I can ping now to RounterB and its LAN

but when I ping Router C, It cannot reach the destination...

Is there something Im missing?
how can I let RouterC know that RouterA exist and its Lan through Router B's Routing table??


uhm anyway, here's the pkt.
www.2shared.com/file/6350732/c620d3a9/defaultroute.html

You just need to configure another static route on router 0 and router 2.
Here is a link to the modified packet tracer configuration:

www.2shared.com/file/6359427/d01fe7b4/defaultroute.html

thanks for the help ^^, i just found out that its better if I use RIP than static routing.. ^^ thanks LOSH

that depend on how big your network is and what level of security you want