Directions: In the sentence given below, four words are highlighted in bold. These words may or may not be in their correct positions. Find the correct combination of words that should be interchanged to make the sentence grammatically correct and contextually meaningful. If the sentence is correct as it is, select 'No correction required'.

Modern architecture is focused on spaces (1) that maximize a building's efficiency (2) and utilizes sustainable energy (3) systems to reduce environmental impact (4).

The correct answer is No correction required.

Step-by-Step Explanation:

To determine whether any of the highlighted words need to be interchanged, let us evaluate the contextual and grammatical correctness of each word in its given position:

1. spaces (1): In the segment "focused on spaces that...", the noun "spaces" refers to the spatial design and physical layouts created in modern architecture. It is grammatically correct as the object of the preposition "on" and makes complete sense contextually.
2. efficiency (2): In the segment "maximize a building's efficiency", the noun "efficiency" appropriately follows the possessive form "building's" to describe optimizing performance and resource use. This is grammatically sound and contextually appropriate.
3. energy (3): In the phrase "utilizes sustainable energy systems", the noun "energy" properly combines with "sustainable" and "systems" to describe renewable power systems. The collocation is natural and meaningful.
4. impact (4): In the phrase "reduce environmental impact", the noun "impact" modified by the adjective "environmental" forms a standard phrase that accurately describes reducing ecological footprint.

Since all four highlighted words are already in their correct positions and the original sentence is both grammatically sound and contextually meaningful, no word swap is necessary.

Therefore, the sentence is correct as it is, making No correction required the correct choice.