2 IP addresses - 1 NIC or 2 NICs

It all really depends on the speed that you need for each link and the amount of configuration you want to go into doing something like this.

Assuming that your NICs are 1Gbps and you put 2 IPs on that one NIC, then the global maximum speed you can reach will be 1Gbps. Obviously if you have two NICs then you will have 2Gbps total maximum speed. (1-1 each)

While configuration of two IPs on one NIC is possible, it generally is more advisable to try to separate networks with NICs whenever possible.

Option B is definitely a better option to go.

The above mentioned part is mainly meant for physical configuration. For virtual environments the speed will still be limited by the interface speed of the card, but assuming that you won't be pushing too much traffic over these interfaces I'd opt for 2 virtual NICs.