Answer:
In B, One card is chosen from a standard deck, it is set aside, then a second card is drawn. That "set aside" is where we have a problem. We began with 52 cards, but now have 51. This fact WILL change the probability or probabilities. Chances of obtaining a red heart from the full 52-card deck are 4/52; whereas chances of obtaining a red heart from the remaining 51 cards (assuming that you got a red heart earlier and set it aside) is 3/51.