The correct answer is: a) Excessive irrigation and poor drainage.
Excessive irrigation can lead to waterlogging, which is when the soil becomes saturated with water. This can cause the soil to become saline, which means that it contains too much salt. Salty soil is not suitable for growing crops, and it can also damage infrastructure.
Poor drainage can also lead to waterlogging. When water cannot drain away from the soil, it can build up and cause the soil to become saturated. This can also lead to salinization.
Industrial pollution, coastal erosion, and deforestation are not the main causes of waterlogging and soil salinization in Punjab.
Industrial pollution can cause water pollution, but it is not a major cause of waterlogging and soil salinization. Coastal erosion can lead to the loss of land, but it is not a major cause of waterlogging and soil salinization. Deforestation can lead to soil erosion, but it is not a major cause of waterlogging and soil salinization.
In conclusion, the main cause of waterlogging and soil salinization in Punjab is excessive irrigation and poor drainage.