The sentence fragment can be corrected by combining it with one of the options provided. The best choice to complete the fragment "the students in" would be:
"the students in" + "is studying Shakespeare"
So the complete sentence would read: "The students in the class is studying Shakespeare." However, the verb "is" should be changed to "are" to correctly agree with the plural subject "students."
The corrected sentence is: "The students in the class are studying Shakespeare."