1. Correct Answer: Option D: 100 km
 2. Explanation:
     To solve this problem, we can use the Pythagorean theorem. The towns P, Q, and R form a right-angled triangle with P as the vertex of the right angle. Here's how we can visualize and solve it:
     ● Step 1: Identify the positions of the towns.  
           ○ Town Q is to the West of P, so we can consider the line segment PQ as the horizontal leg of the triangle.
           ○ Town R is to the South of P, so we can consider the line segment PR as the vertical leg of the triangle.
     ● Step 2: Assign the given distances to the respective line segments.  
           ○ The distance between P and Q (horizontal leg) is 60 km.
           ○ The distance between P and R (vertical leg) is 80 km.
     ● Step 3: Use the Pythagorean theorem to find the distance between Q and R (the hypotenuse of the right triangle).  
           ○ According to the Pythagorean theorem:
         \[
         \text{(Distance between Q and R)}^2 = \text{(Distance between P and Q)}^2 + \text{(Distance between P and R)}^2
         \]
           ○ Substitute the known values:
         \[
         \text{(Distance between Q and R)}^2 = 60^2 + 80^2
         \]
           ○ Calculate the squares:
         \[
         \text{(Distance between Q and R)}^2 = 3600 + 6400 = 10000
         \]
           ○ Take the square root to find the distance:
         \[
         \text{Distance between Q and R} = \sqrt{10000} = 100 \text{ km}
         \]
     Therefore, the distance between Q and R is 100 km.