Final answer:
Helsinki is the Finnish capital with an airport that offers sleep pods, a spa, and more.
Step-by-step explanation:
The answer to the question is D) Helsinki.
Helsinki is the capital of Finland and it has an airport that offers various amenities, including sleep pods and a spa. Helsinki Airport is known for its modern facilities and services, designed to provide a comfortable experience for travelers.
Some of the other options listed in the question, such as Oslo, Stockholm, and Copenhagen, are also capital cities of Nordic countries, but they do not have an airport that offers the same amenities as Helsinki Airport.