If Jan bought 3 lamps for $23.59 each, and a sofa for $769.99, then we can add these prices together for the total amount Jan spent:
23.59 + 23.59 + 23.59 + 769.99 = $840.76
Now we can find out how much sales tax she owes by multiplying the total cost by the sales tax rate:
$840.76 x 7.5% = 840.76 x 0.075 = $63.06
Therefore the answer is B. $63.06