which two cases will statements execute in parallel?

See the table below:

All execution servers are currently available and the sessions use defaults for all parallel settings.
In which two cases will statements execute in parallel?

A.
When parallel hints are used but only if estimated serial execution takes more than 10 seconds.

B.
When parallelism is defined at the statement level.

C.
When the degree of parallelism is explicitly defined in the data dictionary for tables and indexes
accessed by a query.

D.
Parallel DDL statements but only if estimated serial DDL execution time is greater than 10
seconds.

E.
When the degree of parallelism is explicitly defined for tables and indexes but only if estimated
serial execution takes more than 10 seconds.

Explanation:

Incorrect:
A, D, E: When PARALLEL_MIN_TIME_THRESHOLD is set to AUTO the
PARALLEL_MIN_TIME_THRESHOLD is set to 30, not to 10. See note below.
Note:
* parallel_min_time_threshold
PARALLEL_MIN_TIME_THRESHOLD specifies the minimum execution time a statement should
have before the statement is considered for automatic degree of parallelism. By default, this is set
to 30 seconds. Automatic degree of parallelism is only enabled
if PARALLEL_DEGREE_POLICY is set to AUTO or LIMITED.