Implementation walkthrough

The tone of Jane Carlyle’s letter is guarded, and her feelings are always ____ by the wit and pride that made____plea for sympathy impossible for her.

(A) masked.. a direct

(B) bolstered.. a needless

(C) controlled.. a circumspect

(D) enhanced.. an intentional

(E) colored.. an untimely

even though using intuition i know that blank a is something similar to guarded, but i used block of 4
tone of letter → guarded
feeling → exposed

and if you look at it with the perspective of math strategy we have our division word as and (+) which would support guarded

My doubt is which strategy to pick in time like these?

Block of 4 requires there to be an established relationship between two entities that we then map onto a parallel set of entities.

In your example, you used guarded and feelings, but the relationship between these is one of qualification, meaning it’s a grammatical distinction. “Feeling” is not necessarily linked to “exposed”; you can have lots of feelings but deal with them in a guarded way, as is the case here.

Instead, you should go with math strategy, where you correctly identified “and” as the support cue for “guarded”.