No referent to the modifying phrase!!!Please explain.

Using a Doppler ultrasound device, fetal heartbeats can be detected by the twelfth week of pregnancy.

(A) Using a Doppler ultrasound device, fetal heartbeats can be detected by the twelfth week of pregnancy.
(B) Fetal heartbeats can be detected by the twelfth week of pregnancy, using a Doppler ultrasound device.
(C) Detecting fetal heartbeats by the twelfth week of pregnancy, a physician can use a Doppler ultrasound device.
(D) By the twelfth week of pregnancy, fetal heart-beats can be detected using a Doppler ultrasound device by a physician.
(E) Using a Doppler ultrasound device, a physician can detect fetal heartbeats by the twelfth week of pregnancy.



Hi Stacey,
The above is an OG verbal review question. I agree that the correct answer is E, but can’t fully understand the explanation given by OG for the option B being wrong.



For the option B OG states,

The modifying phrase has no referent.


As far I know, Using ,a present participle modifier as well an adverbial modifier, can modify either the verb of the preceding clause or the whole clause altogether. In the option B using modifies the verb ‘detected’ of the preceding clause, i.e; How the fetal heartbeats can be detected? It can be detected using a Doppler ultrasound device. Apparently I couldn’t find anything wrong with the answer B except that it is in passive voice and that was the exact reason for me to prefer E over B.

Am I missing something with the past participle modifier concept here? Is there some rule that
Present participle modifier can modify the verb of the preceding clause only if the doer of the action is present in the clause or in other words it is in the active voice.

Kindly clarify the above doubt and also the OG explanation for the option B.



Thanks,