Which of the following two salts would have a lower solubility. $($You do not need to calculate molar solubility$).$

$K_{\text{s}\text{p}\text{C}\text{a}\text{C}\text{O}3}=5\mathrm{.}0{10}^{-9}O{R}_{sp}SrC{O}_3=5\mathrm{.}6{10}^{-10}$