Final answer:
The question asks about the number of times high-frequency words should be introduced by a program in a week. Based on general teaching practices, introducing these words five times per week could be effective for retention.
Step-by-step explanation:
The question pertains to the frequency with which a well-designed program should introduce high-frequency words during a week. Although the supplied references do not directly answer this specific question, using general pedagogical knowledge, we know that repeated exposure to high-frequency words is crucial for students, particularly in language learning and literacy.
It's commonly suggested that exposure to high-frequency words should ideally happen multiple times throughout the week. The most effective frequency can vary based on the program and the age of the students. Therefore, without a specifically supplied answer choice, one could argue that for diligent retention, introducing these words five times per week could be effective. This would ensure daily exposure during the school week, reinforcing learning and retention.