Read the given statements and conclusions carefully. Assuming that the information given in the statements is true, even if it appears to be at variance with commonly known facts, decide which of the given conclusion(s) logically follow(s) from the statements.
Statements:
1. All priests are teachers.
2. Some priests are singers.
Conclusions:
I. Some singers are teachers.
II. Some singers are priests.

​Statements:
1. All priests are teachers.
2. Some priests are singers.

​Conclusions:
I. Some singers are teachers. (True, all priests are teachers and some priests are singers, that means some singers are priests).
II. Some singers are priests. (True, from statement some priests are singers, that means some singers are priests).

So, ​Both conclusions I and II follows.

Thus, correct option is (b).