The wholesale price of the home audio system is = $264
The electronics store had marked up the price of the system by = 60%
So, the additional price becomes=
= $158.40
Total price of the audio system now becomes = 264+158.40 = $422.40
As Lori was paid commission of = 15% on 422.40, so her commission becomes =

= $63.36
Hence, option D is correct.