You observe the lower limb of the Sun at a sextant altitude (hs) of 31°31.5' on 6 March. The index error is 2.5' on the arc. The height of eye is 76 feet. What is the observed altitude (Ho)?

Correct Answer: Option D — 31°35.3'

Correct hs 31°31.5' by subtracting 2.5' (on the arc) to get 31°29.0'. Subtract dip for 76 feet (-7.9') and add the March Sun altitude correction (+14.2'). The resulting Ho is 31°35.3'. This process aligns with the Nautical Almanac's requirements for converting sextant altitude to observed altitude.