Which of the following pairs indicates the closest macroevolutionary link among the bacteria ...

Which of the following pairs indicates the closest
  macroevolutionary link among the bacteria according
  to the evolutionary history tree in the text?
  a. green sulfur; spirochetes
  b. chlamydias; cyanobacteria
  c. green sulfur; green nonsulfur
  d. spirochetes; proteobacteria
  e. proteobacteria; cyanobacteria

Question 2

Some genes encoding proteins that are essential to
  the survival of the organism are called highly
  conserved sequences. Which of the following is an
  example of one of these proteins?
  a. cytochrome b
  b. muscle structural proteins
  c. carbohydrate hydrolyzing genes
  d. skin pigmentation
  e. keratin