Using regression adjustments $to$ estimate the effects $of$ policy intervention

Suppose you want $to$ examine the effects $of$ a job training program, and estimate the following regression model $todoso$:

widehat$($ earn $98)=4\mathrm{.}5+2\mathrm{.}2$ train $+0\mathrm{.}34$ earn $96+0\mathrm{.}32$educ$-0\mathrm{.}15$ age $+2\mathrm{.}2$ married,

where

earn $98=$ labor market earnings $in1998,in$ thousands $of$ dollars;

train $=1if$ the employee participated $in$ the training program, and $=0$ otherwise;

earn $96=$ labor market earnings $in1996(the$ year before the training program$),in$ thousands $of$ dollars;

educ$=$ years $of$ schooling;

age $=$ age, $in$ years;

married $=1if$ the employee $is$ married, and $=0$ otherwise;

$n=1,140$

$R^2=0\mathrm{.}43$

Using unrestricted regression adjustment, which $of$ the following best represents the estimated equation with full interactions?

$\{\begin{array}{cc}\text{:}& -\end{array}$

$\{\begin{array}{ccc}\text{:}\text{w}\text{i}\text{d}\text{e}\text{h}\text{a}\text{t}& (earn9)=5\mathrm{.}4+3\mathrm{.}5\text{t}\text{r}\text{a}\text{i}\text{n}+0\mathrm{.}4\text{e}\text{a}\text{r}\text{n}96+0\mathrm{.}33\text{e}\text{d}\text{u}\text{c}-0\mathrm{.}21\text{a}\text{g}\text{e}+2\mathrm{.}5\text{m}\text{a}\text{r}\text{r}\text{i}\text{e}\text{d}+0\mathrm{.}17\text{t}\text{r}\text{a}\text{i}\text{n}*(educ\frac{-}{b}ar(educ))+0\mathrm{.}033\text{t}\text{r}\text{a}\text{i}\text{n}*(educ\frac{-}{b}ar(educ))+0\mathrm{.}06\text{t}\text{r}\text{a}\text{i}\text{n}*(educ\frac{-}{b}ar(educ))+1\mathrm{.}42\text{t}\text{r}\text{a}\text{i}\text{n}*(educ\frac{-}{b}ar& (educ))\end{array}$

Using your answer from the preceding question, the estimated average treatment effect $of$ the training program $is$ widehat$({}_{\text{u}\text{r}\text{a}})=$

Which $of$ the following best represents the meaning $of$ the estimated average effect $of$ the training program?

The training program led $to$ a decrease $in1998$ earnings $of$ $$400.$

The training program led $toan$ increase $in1998$ earnings $of$ $$3,500.$

The training program led $to$ a decrease $in1998$ earnings $of$ $$2,500.$

The training program led $to$ a decrease $in1998$ earnings $of$ $$1,420.$