Yahoo showed a fairly large increase in last month’s online-video viewing. How? I’ll give you a hint: it’s news.

Since most of the monthly comScore data is predictable, the blogs have jumped on this… Search Engine Watch called it “colassel as a giant squid,” and TubeFilter called it “massive.”

While 20% growth on a low base isn’t perhaps “colossal” or “massive,” it is impressive for Yahoo. Yahoo always fancied itself as a portal, hence its loss of audience to search-engine giant Google. In early 2000s I would have expected Yahoo to be the rightful owner of the online-video battle. But it hasn’t captured online video despite many attempts.

Now Yahoo has bumped Vevo out for the #3 position last month. Sure, the audience bar chart shows a steep cliff after Google sites (YouTube). YouTube streamed about 50% of the 40 billion video views in February (and has about 3x the viewers of its nearest competitors). But Yahoo’s growth still warrants some exploration.

So what’s going on with Yahoo? Pick below:

a. Yahoo could be doing a better job of convincing its 177 million unique monthly viewers to consume video.

b. Yahoo announced a slate of new comedy programs, and launched the Screen, although these unlikely impacted last month.

c. Yahoo and ABC News partnered in October 2011. That deal accounts for almost half of the news videos watched by U.S. Internet viewers in February… that puts the ABC/Yahoo duo above MSNBC and CNN.

(Hint: pick c, or abc).

News is the new viral, kids.