1) Explanation

Let's analyze the sentence blank by blank:
- "Paradigmatic upheavals often occur after a period of increasing (i) $\qquad$ which creates quandaries for the scientific or cultural status quo."
- "Paradigmatic upheavals" means fundamental, revolutionary changes in thinking or a system.
- These upheavals happen after a period of increasing something that "creates quandaries" (dilemmas, puzzling situations) for the "status quo" (the existing state of affairs).
- If the status quo is facing quandaries, it means the current ways of thinking or models are struggling to explain new observations or solve problems. This suggests a period where things don't fit the established pattern.
- A. concatenation: A series of interconnected things or events. While changes might involve interconnected events, "concatenation" doesn't directly imply a problem or dilemma for the status quo.
- B. aberration: A departure from what is normal, usual, or expected, typically an unwelcome one. This fits perfectly. Increasing departures from the norm would create quandaries for the established way of thinking.
- C. inculcation: The instilling of knowledge or values, usually by persistent instruction. This implies strengthening the status quo's ideas, which is the opposite of creating quandaries for it.

- "As the dominant theoretical models are questioned and (ii) $\qquad$ new models are proposed that may ultimately alter the perceptions of the entire population."
- The "dominant theoretical models are questioned" (meaning challenged).
- The blank describes what happens to these questioned models right before "new models are proposed." If they are questioned, they are likely being attacked or called into doubt.
- D. impugned: Challenged as false, doubted, or attacked. This aligns perfectly with models being "questioned" and subsequently having new models proposed. If something is impugned, its validity is challenged.
- E. emblematized: Made into a symbol. This is irrelevant to the process of models being questioned and replaced.
- F. approbated: Approved or officially sanctioned. This is the opposite of being questioned and potentially replaced.

Putting It Together:

The most logical combination is (B) and (D):
"Paradigmatic upheavals often occur after a period of increasing aberration which creates quandaries for the scientific or cultural status quo. As the dominant theoretical models are questioned and impugned new models are proposed that may ultimately alter the perceptions of the entire population."