Use the Following Description and Table to Answer the Next

Multiple Choice

Use the following description and table to answer the next few questions.
A state education department conducted a study of 1000 primary schools to find out how much parental engagement matters for improving academic performance .They measured parental engagement at each school (on a 1-5 scale) , and used regression analysis to examine the effect of engagement on the percent of students meeting state standards in English language arts .To get a better estimate of the true causal effect of engagement, they controlled for poverty and school size (enrollment) because of a concern that these variables may be influencing both parental involvement and academic performance .The results of various specifications using regression analysis are shown below.
Regression analysis of percent of students meeting ELA standards (various specifications)
$$\begin{array} { | l | c | c | c | c | } \hline & \text { Spec 1 } & \text { Spec 2 } & \text { Spec 3 } & \text { Spec } 4 \\\hline \begin{array} { l } \text { Parental engagernent (1-5 } \\\text { scale) }\end{array} & 13.1 8 ^ { * } & 8 . 2 3^ * & 14.18 ^ { * } & 9.14 ^ { * } \\\hline \text { Poverty (\%/ of students) } & & - 0 . 4 9 ^{*} & & - .47 * \\\hline \text { Enrollment (\# of students) } & & & .013^*& .009^* \\\hline\end{array}$$
NOTE: N=1000 primary schools; dependent variable is percentage of students meeting standards in English language arts (ELA) ; * p < .05
-How did controlling for school size alone change the estimated causal effect of parental engagement?

A) Reduced the effect
B) Increased the effect
C) Eliminated the effect
D) Did not change the effect