# 4. If a and b are constants, the most general ...

4. If a and b are constants, the most general solution of the differential equation

${d^2\over dt^2}+2{dt\over dx}+x=0$ is

(A) ae-t

(B) ae-t +bte-t

(C) aet +bte-t

(D) ae-2t

Hint: