States that impose stringent rules on voting by mail are characterized by which of the following institutional barriers?

The correct answer, which identifies the difficulty in absentee voting, is appropriate because stringent rules on voting by mail can create substantial challenges for voters trying to access and successfully complete the absentee voting process. These difficulties may include strict deadlines for requesting ballots, complicated procedures for completing and returning ballots, and requirements for notarization or witness signatures. As a result, these regulations can discourage or prevent eligible voters from participating in elections, particularly among populations who may have less flexibility or access to resources, such as working individuals or those with disabilities.

In contrast, other options such as weekday voting or difficulty of registration may not directly relate to mail-in voting. Weekday voting generally pertains to in-person voting schedules rather than absentee ballots, and while registration challenges can affect overall voter participation, they do not specifically address the barriers associated with voting by mail. Weak political parties also do not serve as a barrier to mail-in voting; rather, a strong party system could actually facilitate access to voting resources for individuals. Therefore, the focus on absentee voting accurately captures the institutional barriers associated with restrictions on mail-in ballots.