Let's analyze the statements about summons under the CrPC:
(a) is false. Section 61 requires every summons to be in writing and in duplicate.
(b) is false. Section 63 provides a specific procedure for service of summons on corporate bodies and societies.
(d) is false. Section 64 allows service on an adult male member of the family if the person cannot be found, but not on a servant.
(c) is correct. A summons is a judicial order for a specific purpose. It can be issued to compel a person's appearance in court (as an accused or a witness) under Section 61, or it can be issued to compel a person to produce a document or other thing under Section 91.