Final answer:
Option (b), The least important piece of information for an estate executor is the decedent's cost basis on assets.
Step-by-step explanation:
As an executor of an estate, the piece of information that is LEAST important to you is the decedent's cost basis on assets. The decedent's cost basis is less relevant than other values because the basis generally gets stepped up to the fair market value as of the date of death, which is used for tax purposes if the assets are sold.
For estate tax purposes, particularly under United States law, the most important figures are the date of death value of the taxable estate, the value of taxable gifts made by the decedent, if any, and the date of death value of each asset, to properly calculate the estate's liability for estate tax, if applicable.
It's important to note that estate taxes typically only apply to estates exceeding a high value threshold, which, according to the Center on Budget and Policy Priorities, was above $5.43 million in 2015.