Final answer:
The solar wind was the most important effect in clearing the solar nebula of gas and dust, contributing significantly to the formation of the solar system.
Step-by-step explanation:
The process of clearing the solar nebula of gas and dust was a critical step in the formation of our solar system. The most important effect in this process is solar wind. This phenomenon is a continuous stream of charged particles released from the upper atmosphere of the Sun, which sweeps away material in the surrounding space. This solar wind exerted enough force to clear the nebula, thus helping to shape the young solar system. While impacts by planetesimals, the Sun's magnetic field, the asteroid belt, and radiation pressure also played roles, it was the powerful solar wind that was most effective at clearing out the gas and dust.