The Value of Walking

Câu hỏi: Read the following passage and mark the letter A, B, C, or D to indicate the correct word or phrase that best fits each the numbered blanks.
New research reveals that walking just 9.5 kilometers (6 miles) a week may keep your brain sharper as you get older. Scientists suggest that walking may protect aging brains from growing smaller and, in turn, preserve memory in old age.
'Brain size shrinks in late adulthood, which can cause memory problems,' study author Kirk Erickson of the University of Pittsburgh said in a news release. 'Our findings should encourage further well-designed scientific trials of physical exercise in older adults as a very (34) ______ approach for preventing dementia and Alzheimer's disease.' For the study, the team asked 299 dementia-free seniors to record the distance they walked (35) ______ week.
Four years later, the participants were tested to see if they had developed signs of dementia (suy giảm trí nhớ). Then after nine years had passed, scientists scanned the participants' brains to measure size. At the four-year test, researchers discovered subjects (36) ______ walked the most had reduced their risk of developing memory problems by 50%. At the nine-year checkpoint, those who walked at least 9.5 kilometers a week, had brains with a larger (37) ______ than those who didn't walk as much.
This is not the first study to promote the benefits of walking in seniors. (38) ______, last spring, Harvard University found that women who walked regularly at a brisk pace had an almost 40% lower risk of stroke.
(Adapted from Cambridge English Advanced Trainer, 2012)
The word or phrase which best fits the gap (34) is...
A. indicative
B. fortunate
C. ideal
D. promising