To vent your spleen means to voice one's anger, which is what the person in the context does by letting out their anger and frustration.
Context: "Barb leaves, you can't deal with it, so you let out your anger and frustration at her and the company she works for." Claim: "Barb leaves, you cant deal with it, so you vent your spleen at her and the company she works for."
Considering the context, is the claim true, false, or unknown?