Researchers found that people 65 and older who had fish once a week had a 60 % lower risk of Alzheimer 's than those who never or rarely ate fish .
Older people who eat fish at least once a week could cut their risk of Alzheimer 's by more than half , a study suggests .
(See options at the end). If the first sentence is true, is the second one also true?
Options:
(a). no;
(b). yes;
(b).