According to the Turing test: a. when a human can solve a computational problem as well as a computer, the human can be considered intelligent
b. if an observer cannot differentiate between the answers to questions given by a human and those given by a computer, the computer can be said to think
c. a computer must score at least 100 on an IQ test in order to be considered intelligent
d. it must be demonstrated that a computer understands what it is doing before it can be said to think