Answer:
The correct answer is option b. "0".
Step-by-step explanation:
In statistics, a t test is used to estimate the difference between the mean of two groups. The t value indicates how different the means are, if the sample mean is equal to the population mean, the t value will be equal to 0. If the t value is positive the sample mean will be higher than the population mean; while a negative t value indicates that the sample is lower than the population mean.