Explanation:

- Unstable use of management practices: This involves inconsistent application of agricultural and resource management strategies. It can lead to soil erosion, loss of fertility, and other forms of land degradation.

- Inappropriate management practices: These include unsuitable agricultural techniques that harm the environment. For example, excessive use of chemical fertilizers and pesticides can degrade soil quality.

- Both (a) and (b): Both unstable and inappropriate management practices contribute significantly to various types of land degradation. Together, they increase vulnerability to environmental and climatic changes.

- Shifting cultivation: This traditional farming method involves clearing forests for agriculture and moving on once fertility decreases. It contributes to deforestation and soil degradation.

- Correct Answer: Option 3 - Both (a) and (b)