What is the primary danger when transporting liquid cargo in a partially filled tank truck (camion citerne) without internal baffles (cloisons anti-ballant)?

1. Liquid surge (effet de ballant): liquid sloshes forward during braking and sideways in turns, destabilising the vehicle and causing rollover
2. The liquid turns into solid ice in tropical heat
3. The tank creates electrical sparks that short-circuit the starter motor
4. The vehicle's steering wheel rotates backwards automatically