Carry a pen on you and right on your hanf or a pice of paaper or use apps in your phone to write down things
Is this supposed to be a multiple choice?
The correct answer is C.
By definition, a bias is a systematic error that generates a distortion in the forecasted results. It can consist on an overestimating or underestimating a parameter.
For example, sampling bias appears when the sample obtained is not a proper representation of the underlying population.