The sentence states that modern psychoanalysis "bequeathed us an effective heuristic" from Freud but also "is guilty of perpetuating many untruths." This suggests a complex relationship acknowledging Freud's contribution but critical or conflicted about some aspects.
- A. dismissive of - would imply outright rejection, which contradicts the acknowledgment of Freud's contribution.
- B. ambivalent toward - means having mixed feelings or contradictory ideas, which fits well with the sentence's meaning.
- C. condemnatory of - means strongly disapproving, which seems too harsh given the acknowledgment.
- D. indifferent to - suggests no strong opinion, conflicting with the recognition of his legacy and faults.
- E. uninformed about - clearly incorrect since Freud is central to psychoanalysis.

Best choice:
B. ambivalent toward