In property law, which concept assumes there are no significant defects in title?

The correct choice is the concept of marketable title. In property law, a marketable title is one that is free from significant defects and encumbrances that could affect its transferability or value. This type of title assures potential buyers or lenders that the property can be sold or mortgaged without facing legal problems regarding ownership. Having a marketable title means that the property does not have issues such as liens, disputes, or claims from third parties that would hinder the selling process or diminish the property's value.

A material fact involves crucial information that could influence a party's decision, but it does not directly relate to the condition of the title itself. Mechanic's lien is a claim against a property for unpaid work or materials provided, which represents a defect that could affect the marketability of the title. Marital property refers to assets acquired during marriage and is a concept related to family law rather than property title issues. These distinctions clarify why marketable title is the answer tied directly to the assumption of no significant defects in title.