Multiple NOT distinct

A B C
1 x q
2 y w
3 y e
4 z r
5 z t
6 z y

B C
y w
y e
z r
z t
z y

Select B, C
From Table
Where B In
    (Select B From Table
     Group By B
     Having COunt(*) > 1)

select *
from
    my_table
where
    B in
    (select B from my_table group by B having count(*) > 1)

select
  *
from
  my_table t1,
  my_table t2
where
  t1.B = t2.B
and
  t1.C != t2.C

-- apparently you need to use <> instead of != in Access
-- Thanks, Dave!