a time to weep

[artart]

a. This is not a time to weep. It is a time to fight.
b. This is not a time for weeping. It is a time for fighting.

c. This is not the time to weep. It is the time to fight.
d. This is not the time for weeping. It is the time for fighting.

e. This is not a time we should weep. It is a time we should fight.
f. This is not the time we should weep. It is the time we should fight.

Which of the above are correct?

[Linguaphile]

a. This is not a time to weep. It is a time to fight.
b. This is not a time for weeping. It is a time for fighting.

c. This is not the time to weep. It is the time to fight.
d. This is not the time for weeping. It is the time for fighting.

e. This is not a time we should weep. It is a time we should fight.
f. This is not the time we should weep. It is the time we should fight.

Which of the above are correct?

All of them are.
Sentence c sounds the best to me, probably how I might say it myself, if I were to express that sentiment.