can someone confirm?

Obtaining a representative sample from a segregated heterogeneous material requires: Taking multiple random samples from random segments of the desired material. Obtaining one bulk sample from each region of the material. Mixing all regions together and taking multiple random samples. Taking one random bulk sample from the material. None of them are within 10g of the right answer. The number of samples taken from each region of the material to be proportional to the relative size of this region