Answer:
a

b
The nutritionist does not have sufficient evidence to reject the writers claim
Step-by-step explanation:
From the question we are told that
The population mean is 
The sample size is 
The sample mean is 
The standard deviation 
The level of significance is 
Now the
Null Hypothesis is 
Alternative Hypothesis is 
generally the degree of freedom is mathematically represented as



For a significance level of 0.05 and 19 degrees of freedom, the critical value for the t-test is 2.093. This is obtain from the t-distribution table
The test statistic is mathematically evaluated as

substituting values


Since the test statistic is below the critical value then the Null hypothesis can not be rejected
So we can conclude that the nutritionist does not have sufficient evidence to reject the writers claim