Answer:
If mental health is not good, that person will stop taking good care of their body (physical). Then they try to isolate themselves from others (social). Mental health is the biggest issue here.
Explanation:
A the day, this is because it makes the most sense within the sentence.
The effects of poor personal hygiene on health and well being are as follows: prone to diseases, shorter life span (as proven in the medieval days), it could also affect your mental health such as causing depression ir isolation for not taking care of self etc. and it could attract parasites and germs that can infect others just to name a few.
By feeling that they have a purpose in life and have people they care about. Or have people that support them.