In the following question, a number series is given. After the series a number is given followed by a, b, c, d and e. You have to complete the series starting with the given number, following the sequence of original series and answer the question that follows the series.
105 53 27 14 7.5 4.25
85 a b c d e

What will come in place of (c) ?

A

9.5

B

11

C

11.5

D

None of these