The t-shirt's sleeve should cover the lifter's __________.

The correct answer is that the t-shirt's sleeve should cover the lifter's deltoid. In powerlifting, the rules regarding the attire are designed to ensure that lifters are in compliance with uniform standards during competition. The sleeve coverage is crucial not only for uniformity but also for ensuring safety and support during lifts.

The deltoid area refers to the upper part of the arm, specifically the shoulder region that connects the upper arm to the core of the body. Proper coverage ensures that there is adequate support and does not interfere with the athlete's range of motion. This is particularly important during the bench press, where shoulder stability is essential for executing the lift safely and effectively.

Understanding the proper fit of the lifting attire, particularly as it relates to the deltoid, aids in enhancing performance and minimizing the risk of injury during competition. The other options do not align with the specific guidelines regarding sleeve coverage in the context of powerlifting.