Unable to Ping Remote Router

[harshil]

I have 4 LAN Segments at remote location. There are 4 routers and 4 subsequent switches. There is communication between all the routers and switches except one. Routing and NAT is done. When I try to ping router C from Switch A it is successful but when I try to ping the router C again from Router A it is unsuccessful. 

Can also traceroute form Switch A to C - Successful

Router A to C - Unsuccessful

What could be the possible issue here?

[anoop verma]

topology diagram ?

[Mark Malone]

Is there any type of acl in place on router A blocking ICMP traffic to C , or a local ACL on C blocking A incoming or maybe firewall

without seeing configs were only going to be guessing here