Step 1: Malarkey is commonly used in speech such as that is just malarkey, meaning that is nonsense.
Step 2: Check each option against this sense. Intelligent is the opposite quality. Pleasing describes something agreeable, not silly. Puzzled describes a state of confusion in a person, not the quality of the talk itself.
Step 3: Foolishness directly captures the silly, senseless quality that malarkey describes.
\[\boxed{\text{Foolishness}}\]