The PCs do not have a default gateway configured. They cannot send traffic off of their local network without a default gateway. The connection between the two switches in the B and C networks will not provide the functionality you need.
You will need to set the default gateway for each host to the respective router in their network.
I didnt completely rework it, but I see three things
1) take the access list 10 off the 172.16.10.0 network router - its blocking all traffic.
2) most of your pcs are missing default gateways
3) change eigrp 10 to no auto summary
Try this acl as a way to meet your requirement:
Extended IP access list ALLOW_ONLY_B
permit ip host 172.16.30.5 172.16.10.0 0.0.0.255
deny ip any any
(apply on Lab B F0/0: ip access-group ALLOW_ONLY_B in)
I always include the implicit deny explicitly so you can get the counter hits.