Correct Option: C

A multiple independently targetable re-entry vehicle (MIRV) warhead is a collection of separate warheads. By contrast a unitary warhead is a single warhead on a single missile. It provides greater target damage for a given missile payload. With a MIRV warhead, the post-boost (or bus) stage can dispense the warheads against multiple targets across a broad area. It reduces the effectiveness of an anti-ballistic missile system that relies on intercepting individual warheads. While a MIRV attacking missile can have multiple warheads (3–12 on United States missiles and 3-10 on Russian), interceptors may have only one warhead per missile. Thus, in both a military and an economic sense, MIRVs render ABM systems less effective.