Harry tests if mothers of a colicky baby have more postpartum depression symptoms than mothers in general. Twenty-five mothers of a colicky baby have a mean score of 4.4 on a questionnaire that measures postpartum depression symptoms (SD = 2.5). The population mean score on this questionnaire is 2.4. Harry conducts a one-sample t test. What is the t statistic? answer choices are: A) -4 or B) 0.8 or C) 4 or D) 20