Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_18 ( userpics_free VARCHAR, name VARCHAR, registration VARCHAR, yearly_cost_for_paid_account VARCHAR )

### Question ###
What is Userpics Free, when Registration is Open, when Yearly Cost For Paid Account is 'unknown', and when Name is Kraslan?

### Accurate SQL ###

SELECT userpics_free FROM table_name_18 WHERE registration = "open" AND yearly_cost_for_paid_account = "unknown" AND name = "kraslan"