Question $4(2$ Points$)$ An object of mass $m$ rests on a frictionless surtace and is attached to a horizontal ideal spring with spring constant $k.$ The system oscillates with amplitude $A.$ The period of oscillation of this system can be increased by $($circle all that apply$)$

$($a$)$ decreasing $k.$

$($b$)$ decreasing $A.$

$($c$)$ decreasing $m.$

$($d$)$ increasing $k.$

$($e$)$ increasing $A.$

$x(f)$ increasing $m.$