Answer:
d.economic duress
Step-by-step explanation:
The economic duress in simple terms means a party who is entering into a contract frightens or threatens of cancelling the contract or does not act according to the terms of the contract unless the other party in the contract agrees to their demands.
In the context, the conduct of Roger against Karl is probably can be called as the 'economic duress' as Roger informs Karl before the deadline of filing the response that he will not represent himself against IRS unless Karl enters into a deal of an expensive retainer agreement. Thus it is an economic duress that Roger is showing and forcing Karl to agree on his demands.