Selection bias is defined as :

Selection bias is defined as
 
  A) the distortion caused when a sampling method systematically includes or excludes people with certain attitudes from the sample.
   B) instances when the control sample is used incorrectly.
   C) an instance when the results prove that the original method used was invalid.
   D) an instance when the sample to be questioned is chosen randomly.
   E) all of the above

Question -2-

Federalism encourages policy experimentation and innovation.
 
  Indicate whether this statement is true or false.

Question -3-

Federalism allows local leaders to frustrate national policies and hence obstruct action on national problems.
 
  Indicate whether this statement is true or false.

Question -4-

The costs and benefits of government are unequally distributed among the states.
 
  Indicate whether this statement is true or false.