What is the science definition of scale?

The correct answer to this question is option D The missing letter in this series is letter E. From the example above, we can tell that the series follows a 2 -1 -2 letter series. This means a message appears twice, the following message appears once, and the cycle continues.

Option A is wrong because the series started at letter C and not B Option B is incorrect because the series has passed the stage of letter C Option C is false because letter D can only appear once. Option E is wrong because letter F cannot appear before letter E.