In which two subregions of Chile do white grape plantings exceed red grape plantings?

Casablanca and San Antonio are two subregions in Chile known for their cooler climates, which are particularly favorable for growing white grape varieties. The predominant white varieties in these regions include Sauvignon Blanc and Chardonnay. In the Casablanca Valley, the maritime influence from the Pacific Ocean helps to create ideal conditions for these varietals, leading to crisp, aromatic wines. Similarly, the San Antonio Valley, which is a relatively newer subregion, is gaining recognition for its high-quality white wines, particularly from cool-climate grapes.

The excess of white grape plantings over red in these areas reflects the trend of utilizing the specific climatic conditions to enhance the characteristics of white wines. This focus on whites is due to consumer preferences and the successful adaptation of specific varieties that flourish in the climate.

In contrast, while other regions mentioned might have significant plantings, they typically see a more balanced or higher proportion of red grape varieties. Thus, the recognition of Casablanca and San Antonio as subregions where white grape plantings exceed reds is supported by both their climatic conditions and the types of wines produced, making option C the most accurate choice.