In the question below, four words are highlighted, which may not be correctly placed. Choose the pair of words that should be interchanged to make the sentence grammatically correct and meaningful.

Promoting renewable development (A) has become the main priority (B) for sustainable energy (C) in many developing nations (D).

The correct option is Only (A)-(C).

Step-by-step Explanation:

Let's analyze the given sentence and the placement of the highlighted words:

"Promoting renewable development (A) has become the main priority (B) for sustainable energy (C) in many developing nations (D)."

1. Contextual Analysis:
- The adjective "renewable" modifies nouns related to natural resources, most commonly forming the term "renewable energy".
- The term "sustainable development" is a standard global economic and environmental phrase, whereas "renewable development" is contextually awkward here.
- "Priority (B)" and "nations (D)" are placed correctly in their respective positions.

2. Interchanging (A) and (C):
- Replacing development (A) with energy (C) and vice versa gives us the modified sentence:
"Promoting renewable energy has become the main priority for sustainable development in many developing nations."

3. Grammatical Check:
- The sentence structure is complete and fluent, with correct noun-adjective pairings and natural semantic flow throughout.

Therefore, the pair of words that should be interchanged is Only (A)-(C).