Equimolar solutions of the following substances were prepared separately. Which one of these will record the highest $pH$ value?

$BaC{l}_2$ is a salt of strong HCl and strong base $Ba{\left(OH\right)}_2$. So, its aqueous solution is neutral with pH 7. All other salts give acidic solution due to cationic hydrolysis, so their pH is less than 7. Thus, pH value highest for the solution of $BaC{l}_2$.