The Sun has been stable for 5 billion years. What will happen in the next two
stages of its life cycle?
A. First it will contract, and then it will expand and return to its
current size.
B. First it will expand, and then it will contract and return to its current
size.
C. First it will contract, and then it will expand and become much
larger than its current size.
D. First it will expand, and then it will contract and become much
smaller than its current size