Does Zookeeper's C API support Kerberos authentication?

I am running a ZKAuthentication test. 

In the server part, I run zkServer.sh to start ZKserver.

In the client part, I create a C application and active ZK's SASL function. Two authentication methods were chosen. The one is Kerberos， the other is DIGEST-MD5. And i receive two report:

1) using Kerberos

2) using DIGEST-MD5

Do those results mean that the Zookeeper's C API doesn't support Kerberos authentication?