Which of the following is one of the changes imposed by PLTIA?

The Patent Law Treaties Implementation Act (PLTIA) introduced several significant changes to patent law, particularly concerning the revival of priority applications. Under this legislation, priority applications that have been inadvertently abandoned can indeed be revived within a two-month window. This provision ensures that applicants have a chance to rectify unintentional mistakes regarding the filing of priority applications, which can be critical for maintaining their rights and securing filing dates.

Other choices do not align with the updates brought by PLTIA. The requirement to include a claim to secure a filing date has not changed, as claims remain a fundamental part of any patent application. The classification of abandonment as 'unavoidable' and the notion that a claim is not required to file an application are also inconsistent with established patent principles and practices. Therefore, the revival provision as specified in the selected answer accurately reflects one of the primary modifications enforced by the PLTIA.