def filter_trials(trial_info):
    """
    Get indices of correct in-sequence trials of odors A to D.
    """
    rat_correct = trial_info[:, 0] == 1
    in_sequence = trial_info[:, 1] == 1
    not_odor_e = trial_info[:, 3] < 5
    select = rat_correct & in_sequence & not_odor_e
    return select