Which event is likely to be a false positive?

Which event is likely to be a false positive?

A.
Internet Relay Chat signature with an alert context buffer containing #IPS_ROCS Yay

B.
a signature addressing an ActiveX vulnerability alert on a Microsoft developer network
documentation page

C.
an alert for a long HTTP request with an alert context buffer containing a large HTTP GET request

D.
BitTorrent activity detected on ephemeral ports