Option 1 states that the use of chemical fertilisers and excessive use of chemical pesticides are primarily responsible for pollution of water resources.

Option 2 adds live-stock manure and deforestation to the list of practices responsible for water pollution.

Option 3 includes the use of live-stock manure and chemical fertilisers as the main culprits.

Option 4 combines all the options mentioned above, including the use of live-stock manure, chemical fertilisers, and deforestation, as the primary causes of water pollution.

The correct answer is Option 1, as it accurately identifies the two agricultural practices that are primarily responsible for polluting water resources: the use of chemical fertilisers and excessive use of chemical pesticides.