I am not understanding well the available answers for this question "Going back to the card example, which of the following sets of events are independent?"
Thanks for reaching out!
So, in this case we're examining the events in pairs (i.e. A: Draw a Diamond, B: Draw an Ace).
We can state that two events are independent if the conditional and unconditional probabilities are equal (P(A|B ) = P(A)). Hence, if the likelihood of drawing a Diamond (P(A)) is the same as drawing a diamond, provided we knew the card was an Ace (P(A|B )), then the two are independent. In this specific case, P(A) = 1/4 since there are 13 diamonds in the 52-card deck. Simultaneously, there is a single diamond among the 4 aces in the deck, so P(A|B ) = 1/4.
Hence, P(A) = 1/4 = P(A|B ), so the two are independent.
We can try the same for the other pairs and see that's not the case, so this is the only acceptable answer.
Hope this helps!
P.S. We're drawing a single card.