What is the correct form of the sentence? "The professor, along with her students, are attending the conference."
A. The professor, along with her students, is attending the conference.
B. The professor, along with her students, am attending the conference.
C. The professor, along with her students, be attending the conference.
D. The professor, along with her students, are attending the conference.
The correct form is "The professor, along with her students, is attending the conference," treating the singular subject "professor" as the main subject.