Explanation:

- Under anomic conditions (1): Durkheim described anomie as a state of normlessness where norms are either insufficient or unclear. In such conditions, division of labour can become dysfunctional as individuals lack guidance on how to properly integrate into the labour system.

- In highly competitive world (2): While competition can be a factor, Durkheim primarily focused on social solidarity rather than economic competition when assessing dysfunction.

- Inadequate organisation (3): Durkheim stated that insufficient coordination among different parts of the labour system can lead to a lack of integration, making division of labour dysfunctional.

- Division of Labour based on caste system (4): If division of labour is based on rigid caste systems, this can inhibit meritocracy and mobility, leading to dysfunction, as tasks are not distributed based on ability or fit but on predetermined caste roles.

Option: 2 - 1, 3, 4 is the correct answer.