This is going to be B.) the issue number of the source... i hope this helps :) and have a great day!!
I would go with the first the 3. Placing the telescope on the tripod. was chosen by the astronomy club
Choice A is the correct answer.
The 's' and apostrophe after the word singer lets the reader know that something is belonging to the group of singers. The apostrophe will always go after the 's' if we are talking about a group of individuals.
When the choral group began, the singers' voices carried throughout the auditorium.