Efforts to Combat Iran's Development of Nuclear Weapons Include All

Efforts to combat Iran's development of nuclear weapons include all of the following except

A) direct negotiations with Iran.
B) economic sanctions against Iran.
C) persuading countries to refuse importation of Iranian oil.
D) the 2010 assassination of the pro-nuclear weapons Iranian president.
E) using a computer worm to target and destroy Iran's enrichment centrifuges.