Read the dialogue and answer the question.
Selin: I read that some scientists are working on a new vaccine.
Emre: Really? What is the vaccine for?
Selin: It is for a type of cancer. They are doing clinical trials now.
Emre: That sounds promising. I hope it works.
What can we infer about the scientists?
A)They have already found a cure for cancer.
B)They are testing the vaccine on humans.
C)They are working on a vaccine for the flu.
D)They have finished their research.