In preparation for mining an analyst should:

A. explore the relationships between variables.
B. verify completeness and accuracy of the data.
C. clean the data addressing missing values, errors, etc.
D. All of the above.

How many pairs of chromosomes do human body cells contain?

Assume the existence of a bankaccount class. define a derived class, savingsaccount that contains two instance variables: the first a double, named interestrate, and the second an integer named interesttype. the value of the interesttype variable can be 1 for simple interest and 2 for compound interest. there is also a constructor that accepts two parameters: a double that is used to initialize the interestrate variable, and a string that you may assume will contain either "simple", or "compound", and which should be used to initialize the interesttype variable appropriately. there should also be a pair of functions getinterestrate and getinteresttype that return the values of the corresponding data members (as double and int respectively).

Which of these is most responsible for differences between the twentieth century to the twenty-first century?