Explanation
Correct answer: D.
Choice D is the best answer. "To that end" logically signals that the information in this sentence—the students’ creation of a show with six starring female roles—is the product of a goal or desire in the previous sentence (the students’ wish to develop a musical with roles for female actors).
Why the other choices are wrong
Choice A
Choice A is incorrect because "in other words" illogically signals that the information in this sentence is a paraphrase or restatement of the previous information about the students’ wish to develop a musical with roles for female actors. Instead, the students’ show is the product of that desire.
Choice B
Choice B is incorrect because "in summary" illogically signals that the information in this sentence summarizes the previous information about the students’ wish to develop a musical with roles for female actors. Instead, the students’ show is the product of that desire.
Choice C
Choice C is incorrect because "for example" illogically signals that the information in this sentence is merely an example of the previous information about the students’ wish to develop a musical with roles for female actors. Instead, the students’ show is the direct product of that desire.