Which object can be a pulsar?

Which object can be a pulsar?
 
  a. white dwarf b. neutron star
  c. black hole d. None of the other choices are correct.

Question 2

A laser guide star is a true star.
 
  a. True
  b. False
  Indicate whether the statement is true or false

Question 3

White dwarfs have such a low luminosity that even the nearest white dwarfs are not visible to the naked eye.
 
  a. True
  b. False
  Indicate whether the statement is true or false

Question 4

How fast does a pulsar initially spin?
 
  a. 10 times per second b. 1 time per second
  c. 100 times per second d. 1000 times per second