This depends on the taxes that you would pay on the $33,000. I'm going to assume that you would pay 15% taxes on $11,000 of the $33,000 just for the sake of argument. Then you would owe $1,650 at tax time with option C. I'll also put you in the 25% bracket for regular income (again, for the sake of argument), so we will subtract 25% of any student loan interest that you pay. Here's my analysis of your options with these assumptions:

A.) Kill the debt in a year by paying about $5,500 per month. You would pay $2,100 in interest over the year earning $525 back in at tax time, so you would pay about $1,575 more than $64,000 over the year.

B.) Kill the debt in two-and-a-half years by paying about $2,150 per month. You would pay about $5,400 in interest over 2.5 years earning a total of $1,350 back at various tax times, so you would pay about $4,050 more than $64,000 over 2.5 years.

C.) Liquidate the taxable account, then pay off the loans over 6/12 months by paying $5,250/$2,670 per month. You would pay about $550/$1010 in interest over the six months/year earning $135/$250 back at tax time. You also owe $1,650 taxes on the liquidated account. Altogether you will pay about $2,060/$2,400 more than $64,000 over the year.

I am ignoring the fact that you will eventually pay taxes on the taxable account anyway, because you probably won't pay these taxes for a while and I am confident in your ability to minimize your taxes at that point in time. If you think that you would have experienced a taxable event (selling stock for a gain or receiving a taxable dividend, for example) in the taxable account in the near future, you need to add some taxes into options A and B for a more complete analysis.

According to this math, option A nets you the most immediate savings, but the math will change depending on your exact tax situation.