[单选题]
The reason the position of a particle cano7w- obutl -b:.fio +8c xv:gbnot be specifieej g ibl*,18rzapz-h4d with infinite precision is thap -zb 1jli,r48ezg* he
A. exclusion principle.
B. uncertainty principle.
C. photoelectric effect.
D. principle of relativity.
