Nanette Must Pass Through Three Doors as She Walks from Her

Multiple Choice

Nanette must pass through three doors as she walks from her company's foyer to her office. Each of these doors may be locked or unlocked. Let C be the event that at least two doors are in the same condition. List the outcomes
of C. [Let "L" designate "locked" and U" designate "unlocked".]

A) {LLL, LLU, LUL, LUU, ULL, ULU, UUL, UUU}
B) {LLU, LUL, ULL, LUU, ULU, UUL}
C) {LLU, LUL, ULL}
D) None of these.