A voluntary association where the articles are kept secret and any member may transact in his own name possesses which characteristic?

The characteristic of a voluntary association where the articles are kept secret and any member may transact in his own name aligns best with being governed by rules on co-ownership. In such arrangements, the emphasis is on individual members having the authority to act independently of one another, which is a hallmark of co-ownership situations.

In a co-ownership context, each member typically retains personal rights and can engage in transactions without requiring consent or cooperation from other members, echoing the description provided. This contrasts with formal partnerships, where the actions of one partner can legally bind the others, emphasizing a collective approach rather than a personal one.

The other options relate to characteristics that do not necessarily match the elements of the described organization. For instance, having a juridical personality suggests a level of formal recognition and legal separation that does not align with the notion of members acting individually and without shared governance. Similarly, treating members as partners implies a mutual agreement that contradicts the independence one would expect in a co-ownership scenario. Lastly, being governed by provisions on partnership would inherently involve agreements and responsibilities among members that do not exist if only co-ownership rules apply.