Which of the following would best be considered a call to action?

a
"Can we forge against these enemies a grand and global alliance, North and South, East and West, that can assure a more fruitful life for all mankind?"
b
"I do not shrink from this responsibility—I welcome it."
c
"The graves of young Americans who answered the call to service surround the globe."
d
"... let us go forth to lead the land we love, asking His blessing and His help, but knowing that here on earth God's work must truly be our own."