It may be that by focusing primarily on a patient’s mental condition

Hi,

Using latest technology, The problem was identified.

What do you think about above mentioned sentence. Is it correct ?

Yes.
Seems to make sense.
Is it not?

No that sentence is not correct because doer of the action is missing. Who is using the latest technology ?
If we write adverbial modifer (-ing) infront of the sentence then it straight modifies the subject of the sentence and in above sentence subject is the problem and problem itself cant use any technology.

You will see a huge number of official question written on such pattern.

Refer this article : alien-words-not-so-alien-136331.html
And read MGMAT SC guide, chapter 6 (Modifier), page 84.
If you don't have any guide book, then I suggest you to buy MGMAT SC guide and read it 3-4 times line by line. 40% concepts are covered in that book and for remaining 60% concepts solve as many questions possible question on GMATCLUB and read MGMAT forums.

Option B adds meaning that is not intended.
Who is to determine that "mental health professionals" are doing the predictions? This is out of scope in my opinion.[/quote]

I am also not clear on how mental health professionals can be introduced in the answer.

Read MGMAT SC this concept is explained properly in chapter 6. It is something in non underlined portion which demands a human to perform the action of focusing.
Only option B presents humans in the form of mental health professionals.

No other option is satisfying that demand.

This question is not very-very good, because most of the questions describe doer of the action in inverted sentence structure and keep doer away from -ing modifier. In such questions we try to find a answer choice which brings doer near to the -ing modifier to correct the modification error.

Still I would say that this question is not erroneous and you can learn something out of it. What if you get this in real gmat ?

It may be that by focusing primarily on patient's mental condition and on vague and often very speculative psychodynamic factors, mental health professionals lessen the accuracy of their predictions about the patient's future behavior.

generis or other expert

((((((((fact=B: “…by focusing on factors,…” (who is focusing) must come after the coma.
Subject “mental professionals” is needed, since they are doing the action of 'focusing'.
Mental health professional, by focusing primarily on a patient’s mental condition and on vague and often very speculative psychodynamic factors, lessen the accuracy of their predictions about the patient’s future behavior.))))))))))))))


if we have reduce "adj/adv clause" why we have verb "may be " before "by focusing ...." ?????? how we can match the subject although we have verb behind "by...." ??

(A) predictions about the patient’s future behavior decrease in accuracy (incorrect: modifier error)
There are two clauses: first, it may be and second, after comma hence by focusing is modifier therefore it needs a noun. Predictions cannot be modified by focusing. It is humans who can focus
(B) mental health professionals lessen the accuracy of their predictions about the patient’s future behavior (best option)
Mental health professionals can focus thus correct modifier placement
(C) the accuracy of predictions about the patient’s future behavior lessens (incorrect: modifier error)
By focusing primarily cannot modify the accuracy
(D) a decrease in accuracy is seen in predictions about the patient’s future behavior can be predicted less accurately (incorrect: modifier error)
By focusing primarily cannot modify a decrease
(E) the patient’s future behavior can be predicted less accurately (incorrect: modifier error)
Future behaviors cannot be modified by focusing