Define 'vin nature' in winemaking.

'Vin nature' refers to a style of winemaking that emphasizes minimal intervention and aims to produce wine that reflects the true characteristics of the grapes and the terroir. This approach typically involves using organic or biodynamic farming practices and eschewing the use of additives, preservatives, and commercial yeasts. The goal of vin nature is to capture the authentic expression of the vineyard, allowing the wine to develop naturally during fermentation and aging.

In the context of the other options, the inclusion of added sugar or synthetic additives contradicts the principles of vin nature, which prioritizes purity and the natural fermentation process. Similarly, conventional wine production methods often involve various interventions and techniques that divert from the philosophy of minimalism inherent in vin nature. Therefore, option B stands out as the definition that aligns perfectly with the ethos of this winemaking style.