release v.
1) to set free from restraint, confinement, or servitude <~pent-up emotions> <~the brakes>; also: to let go : DISMISS
2) to relieve from something that confines, or burdens <~was released from her promise>
3) to give up in favor of another : RELINQUISH <~ a claim to property>
4) to give permission for publication, performance, exhibition, or sale of; also: to make available to the public <~a new movie>

What is the correct meaning of the word release in the sentence below?

Before the group could record their song, they were told that they had to sign a contract saying that they would release the use of their voices to the record company.
A.
definition 2
B.
definition 1
C.
definition 4
D.
definition 3