In the decay sequence :
$$
{ }_{92}^{238} \mathrm{U} \xrightarrow{-\mathrm{x}_l}{ }_{90}^{234} \mathrm{Th} \xrightarrow{-\mathrm{x}_l}{ }_{91}^{234} \mathrm{~Pa} \xrightarrow{-\mathrm{x}_l}{ }^{234} \mathrm{Z} \xrightarrow{-\mathrm{x}_l}{ }_{90}^{234} \mathrm{Th}
$$
$x_1, x_2, x_3$ and $x_4$ are particles/ radiation emitted by the respective isotopes. The correct option(s) is/are-
