Which is not an obstacle to finding the cause of some effect?

Which is not an obstacle to finding the cause of some effect?
 
  a. We often overlook the real cause.
  b. Some events are just coincidences
  c. Sometimes the real cause is another event correlated with the suspected cause.
  d. Causes sometimes happen after their effects.

Question 2

Broca's discovery of the speech area of the brain may have involved asking all of the following questions except
 
  a. Did the loss of speech cause the stroke?
  b. What did the stroke victims who were unable to speak have in common?
  c. How did stroke victims who were unable to speak differ from others?
  d. Did the severity of the speech problem vary with the size of the affected brain area?

Question 3

The statement, Interviewers rate job applicants more favorably when they wear a nice suit than when they wear casual clothes is an example of a:
 
  a. Theory of behavior
  b. Hypothesis
  c. Explanation of behavior
  d. Law

Question 4

A statement describing the relationship between two or more events is called a
 
  a. theory
  b. principle
  c. concept
  d. law