Explanation:

- Option 1: Horsts

- The uplifted blocks of block mountains are called horsts. A horst is a raised fault block bounded by normal faults.

- Option 2: Grabens

- Grabens are the opposite of horsts. They are blocks of the Earth's crust that have dropped down between two fault lines.

- Option 3: Slopes

- Slopes refer to the inclined surfaces on hills, mountains, or the sides of valleys, not specifically related to block mountain structures.

- Option 4: Cones

- Cones often refer to volcanic structures, not block mountains. They have a conical shape due to volcanic activity.