A Study Examined the Effect of Protein Consumption on Weight $$\begin{array}{l}\begin{array} { l l } \text { Low-Protein Diet}&\text { High-Protein Diet}\\101.3(20.6)&127.5(21.1)\end{array}\end{array}$$

Multiple Choice

A study examined the effect of protein consumption on weight gain in rats. Investigators obtained 14 female rats and randomly assigned 7 of them to a low-protein diet and the other 7 in a high-protein diet. After 60 days, the weight gained by each rat was recorded (in grams) . Here are the summary findings, displayed as "mean (standard deviation) ":
$$\begin{array}{l}\begin{array} { l l } \text { Low-Protein Diet}&\text { High-Protein Diet}\\101.3(20.6) &127.5(21.1) \end{array}\end{array}$$ Researchers want to know if the amount of protein in the rats' diet significantly affects their weight gain.
What should they conclude at significance level 5%?

A) Reject the alternative hypothesis
B) Fail to reject the alternative hypothesis
C) Reject the null hypothesis
D) Fail to reject the null hypothesis