Hi Allie,

Happy to try and help —

The original rule in question, **“If F is not played, L will be”** gives us three potentially valid consequences:

**F out and L in.**

L out and F in.

Both F and L in.

And one outcome that can’t work —

Both F and L being out. (Because notice, when we try to put one out, the rule forces the other in.)

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Answer choice (C), **“Either F or L is played,”** gives us three potentially valid consequences:

**F in and L out
L in and F out
Both F and L in (remember, “either” doesn’t exclude both.)**

And one outcome that can’t work —

Both F and L being out.

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Answer choice (D), **“Either F or L is not played,”** gives us three potentially valid consequences:

**F in and L out
L in and F out
Both F and L out**

And one outcome that can’t work —

Both F and L being in.

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Notice, (C) has the same consequences as the original rule did, but (D) does not. So, (C) is the correct answer.

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I hope that clears things up — check out lessons 13 and 18 (and 31, which is coming up) if you want some additional practice with conditional rules, and if you have any follow-up q’s just let me know —

Mike