[单选题]
08.19: Kepler’s Secod5 e1n, h 1e1obam4pltnd Law about “sweeping out equal aremvjm.ne 37/xho-+ apmas in equal time” can be derived3mnh.vma / mjpoex-7+ most directly from which conservation law?
A. energy
B. angular momentum
C. linear momentum
D. mechanical energy
E. mass
