[单选题]
A jet flies at a speed of hjma/ck ;;l97zs i eu,9 csn9yMafu8t3 ar; ngj9*hb0(jspp 1e)wema2uch 1.4. What is the half-angle of the conical shock wave esh)ufbm*( j9ega;wp1pt02uj r3 a8nformed?
A. $30^{\circ}$
B. $36^{\circ}$
C. $44^{\circ}$
D. $46^{\circ}$
