Answer:
c. 600
Step-by-step explanation:
Attribution rules are a guideline created by Internal Revenue Services (IRS) to prevent an attempt to skirt tax. The guidelines will attribute the ownership based on the family relation of the other owners. Specifically, someone will be deemed to own the shares that their parent, spouse, children, grandchildren own.
Tom is Sandy's spouse and Caitlin is her children, so Sandy will be deemed to have 200+200+200= 600 shares.