Update app.py

app.py

@@ -794,7 +794,7 @@ with gr.Blocks(title="PDF to Audio", css="""
             reasoning_effort = gr.Dropdown(
                 label="Reasoning effort (for reasoning models, e.g. o1, o3, o4)",
                 choices=REASONING_EFFORTS,
-                value=None #"o3-mini", #"o4-mini", #"o1-preview-2024-09-12", #"gpt-4o-mini",
+                value="N/A" #standard selection for non-reasoning models
                 info="Select reasoning effort used.",
             )