Complete the sentence with the correct words.

Food and nutrition expert Peter Bennet reports on his trip to a pretty fishing village on one of the islands of Okinawa, Japan, to find out why the people there live so long. When I first met Makato Okushima, I would have said she was seventy-five, perhaps eighty years old. In fact, she is one hundred years old, ... She is just one of more than 400 people there who are at least one hundred years old. Okinawa has the highest and healthiest concentration of centenarians in the world.

• which is not at all unusual in Okinawa.
• who also looked younger than her 76 years.
• who has studied Okinawa’s centenarians for more than a decade.
• which the Okinawans firmly believe helps to prevent illnesses.
• since my arrival in Okinawa.
• that the family only ate small portions.
• which is a healthy food and very low in calories.