A. B, and C held the red flag, green flag, and yellow flag, respectively, and climbed from the east, south, and west to the top of the mountain. A does not lift the red flag, nor does it lift the red flag from the east. The mountain on the west; B holds the green flag. Can it be launched from this? ['Green flag-bearer from the south.', 'C from the east.', 'It is not the one who holds the yellow flag.', 'B does not mount from the south.']