Which is a correct eco-driving practice that saves fuel and reduces emissions?

1. ①Idle the engine for a long time before setting off to warm it up fully.
2. ②Start and accelerate smoothly, and watch the signals ahead so you can lift off the accelerator early and coast.
3. ③Keep carrying heavy items you do not use in the trunk.
4. ④Accelerate hard just before the light changes and then brake hard at the stop line.