Which Is the Best Counterexample to the Principle in the Following

Which is the best counterexample to the principle in the following Argument from Principle?
[Pay attention to the criteria for good counterexamples from Chapter 6 of Doing Practical Ethics.]
1) It's always wrong to kill an innocent human being.
2) Suicide kills an innocent human being. So, suicide is always wrong.

A) Abortion kills an innocent human being, but it's not wrong.
B) Sometimes, the person who commits suicide is not innocent.
C) Sometimes it clearly is NOT wrong to kill an innocent human being.
D) Suppose that there is a medic during a war who sees a grenade roll into her bunker. The only way to stop the grenade from killing her comrades is to jump on it herself: this will contain the blast but kill her. Perhaps it is not morally required
To jump on the grenade. But, it certainly seems morally permissible -- not wrong!
-- to do it, even if the medic is an innocent human being.