Sam Mueller and Geoffrey Robinson Enter into a Limited Partnership

Sam Mueller and Geoffrey Robinson enter into a limited partnership in which Sam is the general partner and Geoffrey is the limited partner. They borrow $50,000 to start a business. Keeping all rules of naming their businesses in mind, they start a law firm named Robinson-Mueller Legal Associates. Martin Humphrey joins them after eleven months as a general partner but does not include his surname in the name of the business. If the business fails, which of the following is true?

A) Only Sam, being the sole general partner is liable to the creditor.
B) Martin has unlimited personal liability for not including his surname in the name of the business.
C) Geoffrey is liable as a general partner as he included his surname in the business with full knowledge.
D) All three partners are equally liable to the creditor, irrespective of including their surname in the title of the business.