Determine which pairs of the following models are nested models. For each pair of nested models, identify

Question:

Determine which pairs of the following models are "nested" models. For each pair of nested models, identify the complete and reduced model.
a. E(y) = β0 + β1x1 + β2x2
b. E(y) = β0 + β1x1
c. E(y) = β0 + β1x1 + β2x21
d. E(y) = β0 + β1x1 + β2x2 + β3x1x2
e. E(y) = β0 + β1x1 + β2x2 + β3x1x2 + β4x21 + β5x22