There is a sentence that is missing in the paragraph below. Look at the paragraph and decide where (option 1, 2, 3, or 4) the following sentence would best fit.

Sentence: The brain isn’t organized the way you might set up your home office or bathroom medicine cabinet.

Paragraph: ___(1)___. You can’t just put things anywhere you want to. The evolved architecture of the brain is haphazard and disjointed, and incorporates multiple systems, each of which has a mind of its own. ___(2)___. Evolution doesn’t design things and it doesn’t build systems—it settles on systems that, historically, conveyed a survival benefit. There is no overarching, grand planner engineering the systems so that they work harmoniously together. ___(3)___. The brain is more like a big, old house with piecemeal renovations done on every floor, and less like new construction. ___(4)___.

The correct option is Option 1.

To determine where the sentence fits best, we must analyze the logical connection between the sentence to be inserted and the surrounding sentences in the paragraph.

The sentence to insert is:
"The brain isn’t organized the way you might set up your home office or bathroom medicine cabinet."

This sentence introduces an analogy of deliberate, neat human organization (such as organizing files in an office or bottles in a cabinet). Placing this sentence at ___(1)___ sets up a smooth transition to the sentence that immediately follows: "You can’t just put things anywhere you want to." The pronoun "you" and the action of putting "things" in places directly connect to the personal spaces mentioned in the inserted sentence (the office or medicine cabinet).

Additionally, the paragraph goes on to explain that the brain's architecture is "haphazard and disjointed" and lacks a "grand planner." Introducing the idea of structured human organization at the very beginning provides a clear point of contrast for the rest of the paragraph, which explains how evolutionary processes, unlike human planners, build systems incrementally and piecemeal.