Which of the following statement is true

${ }_{78} P t^{192}$ has 78 neutrons

${ }_{84} \mathrm{Po}^{214} \rightarrow { }_{82} \mathrm{Pb}^{210}+\beta^{-}$

${ }_{92} U^{238} \rightarrow {}_{90} \mathrm{Th}^{234}+{ }_2 \mathrm{He}^4$

${ }_{90} \mathrm{Th}^{234} \rightarrow {}_{91} \mathrm{Pa}^{234}+{ }_2 \mathrm{He}^4$