Final answer:
The Benedictine Rules traditionally include the vows of obedience, stability, and 'conversatio morum,' which encompasses poverty and chastity. The vow 'work hard' is not explicitly listed among the Benedictine vows; therefore, 'work hard' is not part of the Benedictine Rules.
Step-by-step explanation:
To answer which vow is not part of the Benedictine Rules, we must consider the traditional vows taken by the Benedictine monks. The Benedictine Order, a group of Christian monastic communities, follows the Rule of Saint Benedict, which includes the vows of obedience, stability, and conversatio morum (fidelity to monastic life), which is often seen as encompassing poverty and chastity.
However, the vow to 'work hard' is not explicitly listed as one of the traditional Benedictine vows. These vows are central to guiding the lives and spiritual practice of Benedictine monks. So, the correct answer is D. work hard.