in a case-control study of computer display exposure and glaucoma, cases and controls were also asked about television viewing habits. Which of the following methods for adjusting for confounding by age is most likely to affect the generalizability of the study findings to the population-at-large?

Select one:

a. Randomization

b. Restriction of study subjects to those less than 50 years old

c. Stratification to several age groups

d. Matching by age plus or minus 5 years

e. Adjustment for age in a regression analysis