Step 1: Understanding the requirement for admitting a new partner.
To admit a new partner in a partnership, all the existing partners must agree unanimously. This ensures that the rights and interests of all existing partners are protected.
Step 2: Identifying the correct condition.
The admission of a new partner cannot be decided by a majority or a subset of the partners. It must be with the consent of all old partners, as partnership agreements typically emphasize unanimity for such critical decisions.