1. The problem asks to identify the angle pair relationship between angles 6 and 7 formed by two parallel lines $l$ and $m$ intersected by a transversal. 2. Important rules for angle pairs with parallel lines and a transversal: - Corresponding angles are in the same relative position at each intersection. - Alternate interior angles lie between the two lines on opposite sides of the transversal. - Same-side interior angles lie between the two lines on the same side of the transversal. - Adjacent angles share a common side and vertex. 3. From the description: - Angles 6 and 7 are on opposite sides of the transversal. - Both angles lie between the two parallel lines $l$ and $m$. 4. Therefore, angles 6 and 7 are alternate interior angles. 5. The correct answer is **B. Alternate interior**.