A: The number of boys participating in the science and technology group is the largest.
(2) 27 > 19 > 16, so most girls join art groups.
A: Most girls join art groups.
(3) Math group: 20+ 16=36 (person)
Art group: 18+27=45 (person)
Science and technology group: 39+ 19=58 (person)
58 > 45 > 36, the total number of people participating in the science and technology group is the largest.
A: The total number of people participating in the science and technology group is the largest.