3. A middle school selects student council members from students in grades 7 to 12, and at least one of the following conditions must be met:
(1) At most 1 person from grade 7;
(2) At most 2 people from grade 8;
(3) At most 3 people from grade 9;
(4) At most 4 people from grade 10;
(5) At most 5 people from grade 11;
(6) At most 6 people from grade 12.
Then, the maximum number of students that can be selected is ( ).
(A) 21
(B) 22
(C) 26
(D) 28
3.C.

Consider the opposite.
If none of the six conditions are met, then at least 2 students from Grade 7; at least 3 students from Grade 8; … at least 7 students from Grade 12 must be selected. In this case, the total number of students selected is at least
$$
2+3+4+5+6+7=27 \text { students. }
$$

Therefore, at most 26 students can be selected.