Over-exploitation of groundwater for irrigation in Punjab has led to:

The correct answer is: d) All of the above

Over-exploitation of groundwater for irrigation in Punjab has led to a number of problems, including:

• Declining water table levels: As more and more groundwater is pumped out, the water table drops. This can make it difficult for farmers to irrigate their crops, and can also lead to problems such as waterlogging and salinity.
• Waterlogging and salinity: When groundwater is pumped out, the water table drops and the soil becomes exposed to air. This can cause the soil to become waterlogged, which can damage crops and make it difficult for them to grow. Waterlogging can also lead to salinity, which is when the soil becomes too salty for crops to grow.
• Increased pumping costs: As the water table drops, it becomes more difficult to pump water out of the ground. This can lead to increased pumping costs for farmers, which can make it more difficult for them to make a profit.

These problems are all serious and have a significant impact on the agricultural sector in Punjab. It is important to find ways to reduce groundwater exploitation and to manage groundwater resources more sustainably.