1) Explanation

Let's break down the sentence to understand the context and the meaning required for the blank:
- "Satire can be both comical and insightful, as Stewart demonstrates:" This opening establishes the dual nature of satire: it's funny ("comical") and it provides understanding ("insightful").
- "Stewart's commentary on politics and popular culture is infused with wit and designed to amuse but still $\qquad$ the viewer."
- "Infused with wit and designed to amuse" covers the "comical" aspect of satire.
- The crucial phrase is "but still $\qquad$ the viewer." The word "but" indicates a contrast or an additional function beyond just amusement. Since satire is also "insightful," the blank must describe how it provides understanding, knowledge, or intellectual benefit to the viewer.

Let's evaluate the given options:
- A. regales: To entertain or amuse (someone). This is synonymous with "amuse," so it does not fit the "but still" contrast, as it would just repeat the idea of amusement.
- B. edifies: To instruct or improve (someone) morally or intellectually; to enlighten. This fits perfectly, as it conveys the idea of providing insight and intellectual benefit to the viewer.
- C. lampoons: To publicly criticize (someone or something) by using ridicule, irony, or satire. While satire often lampoons its subject, the blank refers to what satire does to the viewer. The viewer is not lampooned.
- D. informs: To give (someone) facts or information; to impart knowledge to. This also fits perfectly. It aligns with providing "insight" and intellectual understanding to the viewer.
- E. deceives: To make (someone) believe something that is not true. This is the opposite of providing insight or information.
- F. misleads: To cause (someone) to have a wrong idea or impression about someone or something. This is also the opposite of providing insight or accurate information.

B and D are the correct answer