482VP I think is the correct answer.
The alpha particle is the helium nucleus.
The mass of helium nucleus (⁴₂He) is 4u.
The mass of radioactive atom decreases by 4u. Look at the reaction below:
²²³₈₈Ra ---> ⁴₂He + ²¹⁹₈₆Rn
True.
Dementia's main cause is Alzheimer's disease (50%-70% of cases). You can find it in the DSM-5 as Major Neurocognitive Disorder due to Alzheimer's Disease.
Answer: The answer is the second one