Blank (i)
The phrase "from seemingly innocuous clouds" suggests a sudden and negative change in weather. The word must describe this kind of harsh or stormy condition.
- B. inclement: (of the weather) unpleasantly cold or wet. This fits the description of dangerous, sudden weather changes.
- A. routine and C. sweltering do not fit the context of a dangerous, surprising weather event.

Blank (ii)
The weather change makes the slopes so dangerous that they can catch even experienced hikers off guard.
- E. precarious: Not securely held or in position; dangerously likely to fall or collapse. This perfectly describes a treacherous, unstable situation on a mountain slope.
- D. demanding and F. bucolic do not fit the context of the danger described.

Blank (iii)
The final blank needs a word to describe the kind of hiker who would be most likely to be prepared, yet still be caught unawares by this unpredictable weather.
- H. well-prepared: In a state of readiness for action or any eventuality. This highlights the unexpected nature of the weather, as even someone who has taken precautions is still surprised.
- G. presumptuous and I. intrepid do not fit the context. A presumptuous hiker might be caught unawares, but the phrase "even the most..." implies a person who is typically cautious and ready for a challenge, not arrogant. Intrepid means fearless, but that doesn't imply preparation.