Final answer:
The question asks which star is never visible at 30°N latitude, but without the specific declinations of the stars from question 4, it is impossible to determine which star would be in the south circumpolar zone and therefore never visible. Additional information on the stars' positions is needed for an accurate answer.
Step-by-step explanation:
To determine which star is never visible in the sky for someone living at latitude 30°N, we must understand the concept of circumpolar zones. At 38°N latitude, it is noted that the south celestial pole is 38° below the southern horizon and never visible. Likewise, for someone at 30°N latitude, the south celestial pole would be 30° below their southern horizon. This means that stars within 30° of the south celestial pole are in their south circumpolar zone and would never rise above their horizon.
Unfortunately, the information provided does not explicitly state the declination or sky position of stars A, B, C, D, and E, which is crucial to answer the question definitively. Any star situated more than 30° below the celestial equator (south of -60° declination) would never be visible to someone at 30°N latitude. Without specific details about the declinations of the stars mentioned in question 4, we cannot determine with certainty which star would never be visible from this latitude. More information regarding the positions of these stars is required to provide an accurate answer.