Question

The research was initially considered --- due to its innovative approach, but it later proved to be --- by subsequent studies. 
 

• A. inconclusive
• B. groundbreaking
• C. derivative
• D. valid
• E. unoriginal

Hint:

When a sentence mentions innovation followed by confirmation, pair an adjective showing originality (like groundbreaking) with one showing accuracy or credibility (like valid).

Answer 1

The Correct Option is B, D

Step 1: Understanding the sentence. 
The sentence contrasts the initial perception of the research with what was later proven by studies. The phrase “due to its innovative approach” suggests that the research was seen as highly original or pioneering at first. Later, follow-up studies confirmed its accuracy or legitimacy. 
Step 2: Evaluating the first blank. 
(A) inconclusive — means not providing a clear result; doesn’t fit “innovative approach.” 
(B) groundbreaking — means revolutionary or pioneering; fits perfectly with “innovative.” 
(C) derivative — means unoriginal; opposite meaning. 
(F) experimental — means based on trials; possible, but less precise than “groundbreaking.” 
Step 3: Evaluating the second blank. 
(D) valid — means sound, accurate, or well-supported; fits with “proved to be” by further studies. 
(E) unoriginal — means lacking innovation; doesn’t make sense here. 
Step 4: Conclusion. 
The pair “groundbreaking” and “valid” logically express that the research was first seen as revolutionary and later proven to be scientifically sound. 

Final Answer: (B) groundbreaking and (D) valid