Which of the Following Statements About Spontaneous Mutation Is True

Which of the following statements about spontaneous mutation is True?

A) A single mutation is common but a double mutation is very rare.
B) If the mutation rate to antibiotic A is 10⁻⁹ per cell division, and to antibiotic B is 10⁻⁶ per cell division, the probability of the cell being resistant to both medications is 10⁻¹⁵.
C) If the mutation rate to antibiotic A is 10⁻⁹ per cell division, and to antibiotic B is 10⁻⁶ per cell division, the probability of the cell being resistant to both medications is 10⁻⁵⁴.
D) A frameshift mutation in which three nucleotides are added is less likely to impact a cell that a frameshift mutation in which two nucleotides are deleted.
E) A transposon may insertionally inactivate a gene when it jumps from one place in a genome to another.