What service is provided to IFR/VFR traffic in class E airspace?
a. ATC to IFR and VFR.
b. ATC to IFR; FIS to VFR.
c. ATC to IFR and radio equipped VFR; FIS to non radio VFR.
d. ATC to IFR; Advisory ATC to IFR in VMC; FIS to VFR.