Which of the following is one of the four primary wine-producing regions of New Zealand?

Marlborough is indeed one of the primary wine-producing regions of New Zealand, renowned for its Sauvignon Blanc, which has gained international fame. The region's unique climate, with long sunshine hours, significant rainfall, and diverse soil types, contributes to the distinct flavors and characteristics of the wine produced there. Marlborough leads the country's wine production, representing a significant portion of New Zealand's vineyard area and wine exports.

While other regions like Nelson, Christchurch, and Wellington have their own wine production activities and specialties, they do not hold the same status or recognition as Marlborough in the context of primary wine regions in New Zealand. Nelson is known for its boutique vineyards and some unique varietals, but its production is much smaller compared to Marlborough. Christchurch and Wellington, primarily recognized for different attributes such as urban experiences and cultural richness, do not focus primarily on wine production. Thus, Marlborough is appropriately highlighted as one of the key areas in New Zealand's wine industry.