Final answer:
The minimum age for 7th-grade learners, but the reference information doesn't align with typical age-related questions. Usually, 7th graders are around 12 years old, corresponding with option d) 12 years.
Step-by-step explanation:
The question seems to be referring to the minimum age for learners in a class typically labeled as grade 7. However, the provided reference information does not clearly relate to the question about age, instead, it seems to focus on durations or some sort of measurement in hours. Generally, age requirements can vary by region but if we are to adhere to the common standards in many educational systems, students in the 7th grade are usually around 12 years old.