Answer:
a. probability, when the null hypothesis is true, of obtaining a sample result that is at least as unlikely as what is observed
Explanation:
In Statistics, a p-value also known as the probability value is the probability, when the null hypothesis is true, of obtaining a sample result that is at least as unlikely as what is observed.
The p-values can be calculated by using spreadsheets, statistical software and p-value tables and is widely used in research fields such as economics, physics, sociology, accounting etc.
The p-value can be mathematically expressed as a function of the null hypothesis, H and the random variable, X.