During a pre-drive check, you find the brake fluid level in the reservoir is below the MIN mark. What is the correct judgment and action?

1. ①Less brake fluid makes the pedal lighter, so keep driving as is
2. ②There may be a leak or badly worn brake pads, so postpone driving, have it inspected and refilled
3. ③Fill it up to the MAX mark with tap water
4. ④Brake fluid level does not affect braking, so it can wait until the next regular service