An Analysis of GPA by Class Standing (FR, SO, JR

Multiple Choice

An analysis of GPA by class standing (FR, SO, JR, SR) and major (Social Science [SS] or Natural Science [NS]) revealed the following mean values:
Which of the following conclusions would be most likely?
$\begin{array}{|l|l|l|l|l|}\hline & \mathrm{FR} & \mathrm{SO} & \mathrm{JR} & \mathrm{SR} \\\hline \mathrm{SS} & 2.7 & 2.8 & 3.1 & 3.2 \\\hline \mathrm{NS} & 2.6 & 2.8 & 3.0 & 3.2 \\\hline\end{array}$

A) Significant main effect for class standing
B) Significant main effect for major
C) Significant class standing by major interaction
D) None of the above