Researchers hypothesize that faces are processed faster than other objects, and aim to test the idea with a categorization study. Each participant is shown 30 pictures of faces, and 30 pictures of objects (cars, mailboxes, houses, etc.) and are asked to categorize each picture. Their reaction times are measured in seconds. What statistical test should the researchers use?

A. Simple linear regression

B. Independent samples t test

C. Pearson's r correlation

D. Paired samples t test

E. Single sample t test

F. Z test

G. One-way ANOVA