Charles Clayton Monitors the Daily Performance of His Investment Portfolio

Multiple Choice

Charles Clayton monitors the daily performance of his investment portfolio by recording a "+" or a "-" sign to indicate whether the portfolio's value increased or decreased from the previous day.His record for the last eighteen business days is "- + + - - - + - - + + + - + + + + -".The number of runs in this sample is _________.

A) uncertain
B) four
C) five
D) nine
E) one