Respuesta :
Assuming the underlined sentence is:
"Approximately 250 big name scientists will be winging their way to Washington, D.C. "
The correct answer would be:
D) Approximately 250 well-known scientists will be arriving in Washington, D.C.
The word "big-named" is making reference to a well known, successful important or famous person, product or company, in this case, given is an International Research Institute convention these ones are scientists.