Why is freshness important for ground coffee?

Freshness is crucial for ground coffee because it significantly impacts the flavor and aroma, which are essential for a satisfying coffee experience. Coffee starts to lose its desirable qualities shortly after being ground due to the exposure of the coffee particles to oxygen. This oxidation process leads to a degradation of essential oils and compounds that contribute to the coffee's nuanced flavors and rich aromas. Thus, freshly ground coffee retains these characteristics much better, leading to a more vibrant and enjoyable cup.

While the other options mention aspects related to cost, brewing ease, and longevity, they do not align with the primary reason why consumers and baristas alike prioritize freshness in coffee. Freshly ground coffee offers the best sensory experience, which is why choice C is the correct answer.