`S_(1)` : Mental disability, whether mental retardation or any other developemental disability is not the same as mental illness.
`S_(6)` : And the earlier the better.
P : A person with mental disability can certainly be helped to improve , but mainly in childhood.
Q : But mental disability has no cure.
R : Mental illness has an identifiable cause and may be cured.
S : Not the best doctors nor all the medicines in the world can cure mental disability.
The proper sequence should be

Options

A. PSQR
B. QPRS
C. RQSP
D. SRPQ