Answer: limited partnership
Step-by-step explanation:
A limited partnership simply means a form of partnership whereby some of the partners only contribute financially nd thus will be liable and only to the extent of the amount that they contribute to the partnership m.
In case the company goes into bankruptcy, their personal assets and properties won't be affected. Since Thom invited his parents to invest $40,000 in the enterprise and told them that if they do invest, they would have liabilities in the firm equal to but no greater than their investment, then this is a limited partnership.