Which of the following is correct about the DNA molecules that result from DNA replication?

Which of the following is correct about the
  DNA molecules that result from DNA
  replication?
 
  a. one DNA molecule has both parent strands;
  the other DNA molecule has two new
  strands.
  b. both DNA molecules have two new strands
  each; the parent strands are discarded.
  c. one DNA molecule has a parent strand and
  a new strand; the other DNA molecule has
  two new strands
  d. both DNA molecules have one new strand
  and one old strand
  e. the bottom parts of each new DNA
  molecule are new strands and the top parts
  of each new DNA molecule are old strands

Question 2

The most common source of DNA mutation is
 
  a. cigarette smoke
  b. UV light
  c. errors in DNA replication
  d. errors in protein synthesis
  e. pesticides on the food we eat