THERE ARE CHOICES, and then there are decisions. Early this year, Christian Hackenberg surveyed an enviable choice. ESPN's top-rated high school quarterback had been recruited -- pursued is a better word -- since his sophomore season at Fork Union (Va.) Military Academy. Not surprisingly, Virginia was the first school to make him a scholarship offer. Then came Tennessee. Then came an avalanche of letters and visits by eager men. Hackenberg eventually narrowed his choice to four schools: Alabama, Miami, South Carolina and Penn State. Now came his decision.