Select the correct option:
Even though the phenomenon is uncommon, it may still occur _________ prolonged drought conditions.

The correct option is under.

Step-by-step Explanation:

1. Understand the context: The sentence discusses a phenomenon occurring during or as a result of specific environmental conditions ("prolonged drought conditions").

2. Analyze the prepositions:

• under: Used to indicate experiencing a particular state, circumstance, or environment (e.g., "under conditions", "under pressure", "under heavy rain"). Therefore, "under prolonged drought conditions" is the grammatically correct and natural English collocation.

• towards: Indicates direction or movement in relation to something.

• amidst: Means in the middle of or surrounded by, usually applied to things, people, or chaos, rather than abstract conditional states.

• between: Used to show a relation or position in the space/time separating two points or objects.

3. Conclusion: The appropriate preposition to pair with "conditions" in this sentence is under.