Regarding sematic guess

I chose the first blank to be ‘subjective’ and the second blank to be ‘objective’ from the evidence that they could insert their vision somewhere between the reader’s vision and the reality. Afterwards, when I saw the answer, I chose ‘flexible’ and ‘rigid’.
Most importantly, why the ‘flexible’ and ‘rigid’ option is wrong?
Could anyone tell me where I got it wrong?
@gregmat

for…that conveys support and the idea after that is -ve as we’re talking about how the writers interpose their own vision. This would mean the sentence before is -ve and also we’re using “than” so both the words need to be contrast to each other. Now if you think about semantics, we’re talking about how the writers interpose their own vision (-ve), meaning, literature is much -ve than something neutral.
Flexible is not a negative word. Eliminate on the basis of semantics and connotation and you’ll see how only A makes sense.

Agreed. It means it’s more about connotation right?
The connotation is negative because it says that the vision is inserted in between the REALITY right like subjective than the reality right, like personal feelings?

yeah basically his own understanding rather than focusing on what the reality is…and yes connotation here.