By LD50/30 is denoted: 

A. The dose required to induce death in 30% of a given population by 50 days after irradiation. 

B. The dose required to induce death in 50% of a given population by 30 days after irradiation. 

C. The dose required to induce sublethal damage in 50% of a given population by irradiation with a beam which has a LET value of 30. 

D. The dose required to induce lethal damage in 50% of a given population by irradiation with a beam which has a LET value of 30. 

E. The dose required to induce death of 30% - 50% of the population