Final answer:
The item that does not belong is 'B. descubrir', as it means to discover, which is unrelated to the sustainability-related actions described by the other words: conservar, reciclar, and reducir.
Step-by-step explanation:
The item that does not belong in the list given is B. descubrir. The rest of the items, which are conservar, reciclar, and reducir, all relate to environmental practices aimed at sustainability and minimizing human impact on the planet. Conservar means to conserve, promoting the use of resources in a way that prevents wastage. Reciclar means to recycle, which is the process of converting waste into reusable material. Reducir means to reduce, referring to the reduction of waste and consumption. Descubrir, on the other hand, means to discover, which is not directly related to the environmental practices the other terms refer to.