Which sentence contains a misplaced modifier?

Identify the correct sentence.

Which of the following sentences is incorrect?

Select the underlined word of phrase that is incorrect: When our vacation, we plan to spend three days scuba diving.

Select the incorrect part of the sentence: It as him/who came/running/into the classroom.

Select the incorrect part of the sentence. Every man, woman and child is now aware/ of the terrible consequences of/habit of smoking.

Identify the wrong part of the sentence :

The scientist, who had studied the phenomenon for years, were able to explain the unusual behavior. in great detail, during the conference.