$13-104$ A substance whose Joule$-$Thomson coefficient is negative is throttled to a lower pressure. During this process, $($select the correct statement$)$

$($a$)$ the temperature of the substance will increase.

$($b$)$ the temperature of the substance will decrease.

$($c$)$ the entropy of the substance will remain constant.

$($d$)$ the entropy of the substance will decrease.

$($e$)$ the enthalpy of the substance will decrease.