A manager finds that off$-$the$-$job classroom training has a great impact on the productivity of the employees in her department. However, she also observes that employees over $60$ years of age do not seem to derive much benefit and do not improve with such training. List $($i$)$ the dependent variable, $($ii$)$ independent variable and $($iii$)$ moderating variable in this relationship.

$($i$)$ training, $($ii$)$ employee productivity, $($iii$)60$ years

$($i$)$ employee productivity, $($ii$)$ training, $($iii$)$ age

$($i$)$ benefit, $($ii$)$ employee productivity, $($iii$)$ age

$($i$)$ training, $($ii$)$ employee productivity, $($iii$)$ age