Typically, a design that turns out well has gone through many drafts, each an improvement over the previous one.
Statements
Causal Difference-Maker (what usually allows)
Sketches help us to see the flaws and advantages of a design.
Most Claims (typically / tend to)
Most good designs are the result of many drafts, and each draft usually is an improvement on the previous one.
Most of the time, the tentative parts of the sketch help the designer to see the parts of the design they haven't thought sharply enough about yet.
Evaluate
If we're looking for a safely worded takeaway that combines multiple ideas, it will probably play off the causal sequence of how sketches help designers, and how successive drafts tend to get better.
We'd be speculating a little, but one idea that would tie them all together is to say something like: as a designer goes from one draft to another, she makes a sketch, which helps her see the flaws or under-conceptualized parts of the design and then fix them.
But there's no reason the answer needs to tie everything together. We could make a Trait Overlap inference by saying , or .
Goal
Beware strong wording, out of scope ideas, or unknown comparisons. Look for the correct answer to reinforce the fact that sketches are usually the way that designers figure out the way forward with their design.