Answer:
C) "We'd all hoped that there would be enough overlap that our previously developed MERS vaccine would be helpful in this case"
Step-by-step explanation:
This is the conclusion from the article "Search speeds up for vaccine against the new
coronavirus" which deals with existing efforts and problems in making an efficient vaccine against the new coronavirus.
Looking at the conclusion and the given answers we can see that C. is the best fitting answer because it suggests the scientist's hope that an already existing vaccine could be helpful with the new disease.
That basically means that vaccines we currently have on our disposal, can be used as a basis for developing a new vaccine, if the antigens (genetic makeup) of the causing agents overlap sufficiently.