Answer: The unintended, undesirable effect is morally tolerable if it brings a good result.
Explanation: The doctrine (or principle) of double effect is often invoked to explain the permissibility of an action that causes a serious harm.
According to the principle of double effect, sometimes it is permissible to cause a harm as a side effect (or “double effect”) of bringing about a good result even though it would not be permissible to cause such a harm as a means to bringing about the same good end.