You observe the lower limb of the Sun at a sextant altitude (hs) of 34°51.4' on 18 October. The index error is 2.0' off the arc. The height of eye is 54 feet (16.5 meters). What is the observed altitude (Ho)?

Correct Answer: Option B — 35°01.2'

Observed altitude (Ho) is derived by applying index error (on the arc is subtracted, off the arc is added) and dip correction for height of eye, followed by semi-diameter and refraction adjustments from the Nautical Almanac to find the true center of the body.