The problem of external validity refers to the generalizability of results. (True or false?)

The problem of external validity refers to the generalizability of results.
 
  Indicate whether the statement is true or false

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Whenever two variables are correlated, we may assume that one is the cause of the other.
 
  Indicate whether the statement is true or false

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Which of the following statements is true about client recruitment and retention in experimental and quasi-experimental evaluations in social work agencies?
 
  A) Referring agencies almost never dump clients that they don't want to serve.
 B) Referring agencies are usually eager to refer clients.
 C) Referring agencies might resent having their referrals assigned to a control condition.
 D) Clients usually welcome the use of randomized procedures to determine which service they receive.