[单选题]
06.47: The sub-atomi4r x(sol)ab s.qx kd37a2dwu ;-ly *tgc make-up of a proton is
A. 2 up quarks and a down quark
B. 2 down quarks and an up quark
C. 1 up quark, 1 down quark, and 1 top quark
D. 1 up quark, 1 strange quark, and 1 bottom quark
E. 2 strange quarks and 1 charmed quark
