Europe and Asia form one continuous landmass, Eurasia, with no continuous physical barrier separating them. The conventional line runs along the Ural Mountains, the Ural River, the Caspian Sea, the Greater Caucasus, the Black Sea and the Turkish straits, but this is a human convention rather than a physical fact, and the modern division reflects East-West cultural, linguistic and ethnic differences that vary on a spectrum rather than falling at a sharp line.
What would resolve this Nothing in physical geography can resolve this, since the boundary is conventional by construction; what would change the answer is a shift in which convention geographers, national governments and international bodies choose to follow, which has already moved more than once historically.
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