Stat 100

[Alex]

Crap. I'm partly to blame for b being wrong. GD saw that mistake on your part of using the odds on the wrong side but then I flipped them around again in helping.

Part C is the difficulty of trying to help without the class context. Odds are that was a specific point in the chapter, though I'd argue the answer you gave is a subset of the answer he was looking for. GD's answer is still mostly correct (though adding the word "significantly" to "will not change" might make it better). It just isn't the assumption being sought.

Part D was just a continuation of the same mistake in Part B of having flipped the odds of the two outcomes.