[单选题]
The Q value for a particulv0d k/ha*pfs r8m )zb8ar reaction is ua4mfp87 : kbmjsh8k ;-2.4 MeV, and the reaction's threshold energy is 9.60 MeV. What is the ratio of the mass of the incident particle to the mass of the stationary tkmm ua4j; 8hs78b:fkp arget nucleus?