SELECT B1, B2, B3, C1, C2, C3
FROM A
INNER JOIN AB ON A.id = AB.A_id
INNER JOIN B ON B.id = AB.B_id
INNER JOIN AC ON A.id=AC.A_id
INNER JOIN C ON C.id = AC.C_ID
EDIT:
If the columns in the tables have the same names (e.g. there is a colum B.column1 and a column C.column1) do:
SELECT B.column1, B.B1, B.B2, B.B3, C.column1, C.C1, C.C2, C.C3
FROM A
INNER JOIN AB ON A.id = AB.A_id
INNER JOIN B ON B.id = AB.B_id
INNER JOIN AC ON A.id=AC.A_id
INNER JOIN C ON C.id = AC.C_ID
EDIT 2: For long table names you can do:
SELECT b.B1, b.B2, b.B3, c.C1, c.C2, c.C3
FROM A_LONG_NAME a
INNER JOIN AB ON a.id = AB.A_id
INNER JOIN B_LONG_NAME b ON b.id = AB.B_id
INNER JOIN AC ON a.id=AC.A_id
INNER JOIN C_LONG_TABLE_NAME c ON c.id = AC.C_ID