Usage of evolve, emerge, arose, issue?

[Giang93]

Choose the best answer for the question

When the truth about the blackmail attempt finally _____ , we were all astonished to hear who the culprit was .

A. evolved B. emerged
C. arose D. issued

And also , please tell me the differences between 4 above answers .
Thanks so much in advance :wink:

[Mister Micawber]

.
Emerged (= came out, appeared)

Briefly:

Evolved = changed and developed
Arose = came from nothing
Issued = came out of an aperture, physical or metaphorical.
.
_________________
Native English teacher at Mister Micawber's