What are the prescribed virtues for the four cosmic ages (Yugas) as mentioned in Chapter 38, and which one is emphasized for the current age?

Chapter 38 of the Sai Satcharitra references the scriptures of human duty to outline the primary virtues for each of the four cosmic ages. It specifies that Penance was the key practice in the Krita age, Knowledge in the Treta age, and Sacrifice in the Dvapara age. For the current era, the Kali age, the chapter clearly states that Charity is the prescribed path. It further elaborates that among all charitable acts, the regular practice of food donation (Annadan) is the foremost among all deeds and the highest secret for quenching hunger, making it the most meritorious act.