Two samples A and B sharing the same empirical formula of C$9$H$10$O$2,$ were

examined with $1$H NMR and electrospray mass$-$spectrometry $($negative mode$).$ The results are as follows.

A$.1$H NMR $\backslash$delta $,$ ppm: $12\mathrm{.}1($s$),1$H; $8\mathrm{.}09($d$),2$H; $7\mathrm{.}03($d$),2$H; $2\mathrm{.}72($q$),2$H; $1\mathrm{.}18($t$),3$H$.$

ESI$-$MS$(-)$ Parent peak m$/$z $149$ fragmenting $($MS$2)$: m$/$z $105.$

B$.1$H NMR $\backslash$delta $,$ ppm: $8\mathrm{.}06($d$),2$H; $7\mathrm{.}55($dd$),2$H; $7\mathrm{.}68($t$),1$H; $4\mathrm{.}30($q$),2$H; $1\mathrm{.}30($t$),3$H$.$

ESI$-$MS$(-)$ Parent peak m$/$z $149$ fragmenting $($MS$2)$: m$/$z $121$; $77.$ Determine the structure of both compounds.