What is the primary cause of wet clutch slippage when using standard automotive engine oil instead of motorcycle-specific oil?

1. Automotive engine oils often contain friction modifiers that reduce friction below the coefficient required for the clutch plates to lock and transfer torque.
2. Automotive oils have a much higher viscosity rating that physically pushes the clutch plates apart, preventing mechanical contact.
3. Automotive oils are formulated with high acid levels that chemically dissolve the organic lining of the clutch friction discs.
4. Automotive oils generate high static electricity inside the crankcase, causing the steel plates to magnetically repel each other.