The ventilation coefficient measures the ability of air to move and circulate in a space. A higher ventilation coefficient indicates better air movement and therefore a lower potential for air pollution.

Option 1 states that the ventilation coefficient is greater than 11,000 m2/s. This implies a very high air movement and suggests a lower potential for air pollution.

Option 2 states that the ventilation coefficient is greater than 7,600 m2/s. Again, this suggests good air movement and a lower potential for air pollution.

Option 3 states that the ventilation coefficient is less than 3,600 m2/s. This implies poor air movement and a higher potential for air pollution.

Option 4, the correct answer, states that the ventilation coefficient is less than 6,000 m2/s. This also suggests limited air movement and a higher potential for air pollution.