a) In what way does their research contribute to the greater good?
The research helps the U.S. military as it seeks new ways for soldiers to transmit information without the enemy knowing.

b) What questions did the scientist pose that led to the research that s/he did?

Instead of trying to decode the inner workings of cells, he used cells to encode some secret messages of his own

c) What field of science does this fall into? (Biology, chemistry, physics, etc.?)

biology

Dear David Walt ,
I enjoyed reading your intriguing article.Your work seems very intresting.I have two qusetions though.How can you build the clever sensors if you could only see them with a microscope.And how can they identify individual proteins inside cells.
                                                                                                           sincerly,
                                                                                                                     Muaz