The D&D style guide is fairly prescriptive (which I think is good) but that means most twists on the format don’t have that stamp of approval like other shiny D&D products.
Frankly, the best way to indicate skill challenges and narrative conflict might not be in either of these two “official” versions, but my writerly-robot brain thinks one must succeed over the other in most use cases.
So, playing devil’s advocate.
Maybe A is the best option. For instance, considering the message isn’t player facing and needs to be quick to look-up for the GM, it makes me consider order of phrases in addition to quantity of characters. The more words there are, the less each word matters.
Technically the characters could intimidate, deceive, sneak past, climb through a window, attack, cast a spell, etc, etc. Whenever someone writes B they usually try to amend extra conditions or fictional positioning, but is that time wasted? How far can we bury the game’s mechanical trigger (the DC in D&D) before we’re looking at a large paragraph with the “if this, then that” at the end next to the start of another narrative option? If we’re going to try framing the characters, the logical conclusion is to write lots of different DCs. But that seems like a bad idea regardless of which two options we use.