Which of These Statements About Open Star Clusters Is TRUE

Which of these statements about open star clusters is TRUE?

A) Open star clusters slowly condense into globular clusters as the stars drive off the remaining interstellar dust and gas.
B) One star in an open cluster eventually undergoes a supernova explosion that quickly disperses the other stars.
C) As open star clusters slowly condense, their residual rotation spins them into a flat pancake shape and they become spiral galaxies.
D) The motions of individual stars are such that all open clusters eventually disperse.