Person "A" will be inheriting $100,000.
An inheritance of less than $11.4M is not taxable or reportable on any tax return. Numerous exceptions apply. Since you give no further details, I'm not going into further detail on any possible or probable exceptions.
Is the initial funding of the trust a taxable event?
No more than depositing the money in a bank savings account is a taxable event. (It's not)
Before making "ANY" type of investment, you should consult with a qualified financial/tax advisor anyway. Laws differ quite significantly state to state.
