"3 va después de 5 y entre 7 y 12" = "3 goes after 5, and between 7 and 12"
This eliminates A and D (3 is not between 7 and 12 in either choice).
"5 va antes de 12 y entre 7 y 3" = "5 goes after 12, and between 7 and 3"
This eliminates C (5 is not between 7 and 3).
So the correct sequence is B.