Look at this series: F2, __, D8, C16, B32, ... What number should fill the blank? Choices.
A) A16
B) G4
C) E4
D) E3
E) None
Explanation: The letters decrease by 1; the numbers are multiplied by 2.   Answer: Option E4
<result>C</result>
Look at this series: F2, __, D8, C16, B32, ... What number should fill the blank?