This is a difficult one. Took 3 minutes to do this. Hope I am correct, not sure though.

The playwright Bertolt Brecht staged his plays using a technique known as Verfremdungseffekt or the ‘alienation effect’ to prevent his audience from becoming too involved with the action taking place on the stage, thereby enabling viewers to reflect intellectually on the themes presented to them. While this technique was probably usable in a pre‐World War II era, as then it was still possible to expect art to present objective perspectives on reality, it is clearly invalid in the twenty‐first century.

Which of the following can most properly be concluded from the statements above?

A. Objective perspectives on reality can be presented by art in the twenty‐first century provided that it uses techniques other than the alienation effect.
- The argument clearly states that 21st century does not expect objective perspectives. So this is ruled out.
B. Most art in the pre‐World War II era was expected to present objective perspectives on reality.
- the argument never says this anywhere
C. The alienation effect is invalid in the twenty‐first century since artists no longer want to distance audiences from their work.
- the argument does not talk about what an artists wants/doesn't want
D. Presenting unprejudiced views on reality is instrumental to using the technique of alienation effect.
- this sounds closest to what the argument is saying. the key is to assume objective perspective is 'unprejudiced' view.
E. Implementation of the alienation technique led to the loss of objective perspectives in art.
- there is no evidence for this anywhere in the argument

Based on this, IMO the answer is
_________________

What can be concluded on the basis of premise? It is that in the Post World War II era - technique known as alienation effect is invalid and that the technique prevents audiences from becoming too involved with the action taking place on the stage, and thus they can take an unprejudiced opinion.

Which of the following can most properly be concluded from the statements above?

A. Objective perspectives on reality can be presented by art in the twenty‐first century provided that it uses techniques other than the alienation effect.
- Nothing can be concluded about other techniques. We are not even talking about them.

B. Most art in the pre‐World War II era was expected to present objective perspectives on reality.
- 'Most'? Nowhere it is said that art was trying to do this.

C. The alienation effect is invalid in the twenty‐first century since artists no longer want to distance audiences from their work.
- The argument does not talk about what an artists wants or doesn't want

D. Presenting unprejudiced views on reality is instrumental to using the technique of alienation effect.
- Yes. Unprejudiced may be very airtight but this is correct.

E. Implementation of the alienation technique led to the loss of objective perspectives in art.
- The argument does not talk about this.

D it is.

Option C tells us why this technique is invalid in 21st century since artists no longer want to distance audiences from their work.
if we try to answer the question "why this technique is invalid in the 21st century" from the question stem
"While this technique was probably usable in a pre‐World War II era, as then it was still possible to expect art to present objective perspectives on reality, it is clearly invalid in the twenty‐first century."

we get the answer that the technique is invalid in the 21st century because it is not possible to expect art to present objective perspectives on reality.
if we add D
Presenting unprejudiced views on reality is instrumental to using the technique of alienation effect.
that's why "D".

That's my analysis, experts comments will bring in more clarity.