Salami crisis is the fuse leading to Solon's reform, that is, the direct cause. The Salami crisis has fully exposed the corruption and incompetence of the Athens government, and the social contradictions have become more acute. In this case, solving contradictions has become a top priority, so it is necessary to reform. Therefore, choose A, which is also the inevitability of Solon's reform.

Option B is the possibility of Solon's reform. Solon came to power, which provided him with possible conditions for reform.