[单选题]
18.49: A particle has a t :lqqg *);f:x;cbqg qpotaribz6z6yu5/o.k 82d vhpdgeu gd6 h: ;l energy of 500 MeV and a linear momentum of 300 $\frac{MeV}{c}$. What is the mass of the particle?
A. 800$\frac{MeV}{c^2}$
B. 583$\frac{MeV}{c^2}$
C. 400$\frac{MeV}{c^2}$
D. 267$\frac{MeV}{c^2}$
E. 200$\frac{MeV}{c^2}$