You observe the lower limb of the Sun at a sextant altitude (hs) of 37°47.2' on 11 October. The index error is 3.0' off the arc. The height of eye is 63 feet (19.2 meters). What is the observed altitude (Ho)?

Correct Answer: Option D — 37°57.5'

Adjust hs 37°47.2' by adding 3.0' (off the arc) to obtain 37°50.2'. Subtract dip for 19.2m (-7.7') and add the October Sun altitude correction (+15.0'). The final Ho is 37°57.5'. This calculation follows the standard celestial navigation workflow outlined in Bowditch for determining observed altitude.