Delta II reads as Delta Two or Delta the Second?

Context:

The spacecraft were launched aboard a United Launch Alliance Delta II rocket. GRAIL mission controllers acquired a signal from GRAIL-A at 10:29 a.m. EDT (7:29 a.m. PDT). GRAIL-B's signal was received eight minutes later. The telemetry downlinked from both spacecraft indicates they have deployed their solar panels and are operating as expected.

More:
http://www.sciencedaily.com/releases/2011/09/110910172803.htm