All of the Following Project or System Breakdowns Occurred as a Result

All of the following project or system breakdowns occurred as a result of software errors, except:

A) the 9-hour failure of the AT&T long-distance network in 1990.
B) massive radiation overdoses by Therac-25 radiation therapy machines between 1985 and 1987.
C) a U.S. Patriot Missile battery's failure to track and intercept an incoming Iraqi Scud missile that killed and injured American troops in Saudi Arabia during the Persian Gulf War in 1991.
D) the Mars Climate Orbiter entering the Martian atmosphere about 100 kilometers lower than expected, causing the craft to burn up.
E) periodically miscalculated spreadsheet data completed on computers manufactured by IBM, Compaq, Dell, Gateway 2000, and other IBM-compatible PCs beginning in 1994.