The correct answer is (a) Section 139B.
Section 139B of the Code of Civil Procedure deals with the exemption of members of legislative bodies from arrest and detention. It states that no member of Parliament or State Legislature shall be arrested or detained in any civil proceeding during the session of Parliament or the Legislature, or while going to or returning from Parliament or the Legislature.
The other options are incorrect because they do not deal with the exemption of members of legislative bodies from arrest and detention. Section 132A deals with the service of summons, Section 135A deals with the execution of decrees, and Section 140A deals with the attachment of property.