$4.$ Petra, age $55,$ contributed $$5,000$ as her first contribution to a Roth IRA in May of this year and died six months later. Petra$$s $26-$year$-$old daughter, Portia, was listed as the sole beneficiary. Which of the following correctly represents the tax treatment of any distributions Portia takes, or must take, from the inherited Roth IRA?$$

a$.$ Portia can take tax$-$free distributions based on her life expectancy.$$

b$.$ Portia can take tax$-$free distributions based on Petra$$s life expectancy.$$

c$.$ Portia can take distributions based on Roth IRA distribution ordering rules until the account is five years old, and must distribute all of the account assets by the end of the year containing the $10$th anniversary of her mother$$s death.$$

d$.$ Portia cannot take any distributions until the account is five years old, at which point distributions will be based on her life expectancy.$$