Explanation

There are three on-off switches on a control panel A, B, and C. They have to be changed from the initial setting to a second setting according to the following conditions:

1. In case switches A and B are the only switches on in the initial setting, then turn on switch C.
2. In case all three switches are on the initial setting, then turn off the switch C.
3. For any other initial setting, turn on all switches that are off and turn off all switches, if any, that are on.

Question:

In case all three switches are on in the second setting, which among the following could be the initial setting?

A) A on, B on, C on.

B) A on, B on, C off.

C) A on, B off, C on.

D) A on, B off, C off.

E)  A off, B on, C off.