B for me.
Because of the enormous research and development expenditures required to survive in the electronics industry, an industry marked by rapid innovation and volatile demand, such firms tend to be very large.
we need to have 'firms' for this to make sense... otherwise R&D expenditures required to survie, so B and E survive. E isn't parallel because of the possessive.
Good to see you back u2lover.
I concur with your answer