In the 2000s, the annual rate of increase in the average salary of a s

In the 2000s, the annual rate of increase in the average salary of a software engineer was nearly twice as fast as the 1990s.


A twice as fast as
B twice as fast as it was in
C twice that of
D two times faster than that of
E two times greater than

1. We are not comparing the decades. Hence, A and E are out.
2. Unless we can call the increases as one time, two times, the phrase 'two times' is not useful. You cannot describe a quantum in countable times. Therefore, D is out.
3. The rate of increase does not have speed. We can say-- Tom grows faster than Dick. However, we cannot say Tom's growth rate is faster than Dick's. Therefore, B is out.
C is the answer avoiding the above-said pitfalls. '
Generally, 'two times' is used more in informal daily conversations than 'twice' used in formal writing.