Concept:
Medical termination of pregnancy is legally regulated. It cannot be performed at any time or for any reason without following legal conditions.
Step 1: Understanding legal permission.
The law permits medical termination of pregnancy only under specified conditions.
Step 2: Gestational limit.
The permission also depends on the duration of pregnancy. Termination must be within legally allowed gestational limits.
Step 3: Why other options are wrong.
It is not permitted anytime.
Police approval is not the general requirement.
It is not restricted only to married women.
Step 4: Final answer.
Therefore, medical termination of pregnancy is permitted under specified conditions and gestational limits.
\[
\boxed{\text{Under specified conditions and gestational limits}}
\]