Not sure....I have only heard of a and b with stage II. Cancer usually goes from 1 to 4, with different levels in between. For example, I was a IIa.
Stage II is still considered "early", as it has not apparently spread beyond the local area. However, it could have spread to the nodes which can still mean it is serious. Serious, but treatable. Some people who have cancer spread to the lymph nodes are treated and never have to deal with cancer again.