You observe the lower limb of the Sun at a sextant altitude (hs) of 22°58.6' on 16 June. The index error is 2.0' off the arc. The height of eye is 61 feet. What is the observed altitude (Ho)?

Correct Answer: Option B — 23°06.7'

Apply corrections to the sextant altitude (hs) in the order: index error, dip (height of eye), and total correction (refraction and parallax). With a 2.0' off-the-arc index error, 61-foot height of eye, and standard atmospheric conditions, the resulting observed altitude (Ho) is 23°06.7' per the Nautical Almanac procedures.