To answer the above question, the relevant sentence is: The subordinate salutes first and maintains the salute until the superior has responded in kind.
This justifies what answer for what question? Q & A:
Passage: Since 1917, the British Army's salute has been given with the right hand palm facing forwards with the fingers almost touching the cap or beret. Before 1917, the salute was given with whichever hand was furthest from the person being saluted, whether that was the right or the left. The salute is given to acknowledge the Queen's commission. A salute may not be given unless a soldier is wearing his regimental headdress, for example a Beret, Caubeen, Tam o' Shanter, Glengarry, field service cap or peaked cap. This does not apply to members of The Blues and Royals (RHG / 1stD) The Household Cavalry who, after The Battle of Warburg were allowed to salute without headdress. If a soldier or officer is not wearing headdress then he or she must come to attention instead of giving / returning the salute. The subordinate salutes first and maintains the salute until the superior has responded in kind.

Question: Based on this passage, who do you salute in the british army?
the superior