C is a class B address where the first two octets identify the network. Since none of the remaining bits are set, the all 0s indicates the network address for that subnet mask.
Bills-MacBook-Pro:~ lww$ ping 188.8.131.52
IMO, the question is bogus. Given an appropriate mask, 184.108.40.206 is a perfectly valid IP address. For example, 220.127.116.11/13 works just fine:...Really, CIDR has been around since 1992, can't we just forget about IP address classes already?