Which of the Following Are Thought to Cause Aging

Multiple Choice

Which of the following are thought to cause aging?

A) Death genes are turned on later in life causing cells to deteriorate.
B) Free radicals damage the DNA of a cell past the point where successful accurate replication can occur.
C) Mitochondrial DNA damage results in the loss of proteins and therefore energy production ability.
D) After a certain number of cell divisions,a cell line is pre-programmed to stop dividing and dies.
E) All of these are theories on why we age.