44.在所求點B整置經緯儀，向已知點A實施三角高程測量，測得垂直角為a，儀器高為i，覘標高 為z，AB兩點間之水平距離為D，則B點之高程Hb為：
(A)HB = HA + Dxtana + i —z
(B)HB = HA + Dxtana —i + z
(C)HB = HA—Dxtana —i + z
(D)HB = HA —Dxtana + i —z。