The concept of the value chain was developed by

Which part of the design specification explains to those who will actually develop the final form why this form exists and how it will be used so that they can make the appropriate implementation decisions?

A) System description B) Narrative overview C) Sample design D) Testing and usability assessment E) Project overview

An unbiased estimator of the variance of the estimator of ? follows from the fact that the samples in each stratum are independent of one another

Indicate whether the statement is true or false