What does “different licence for derivative works” mean?

[realpixelcode]

You may add Your own copyright statement to Your modifications and may provide additional or different license terms and conditions for use, reproduction, or distribution of Your modifications, or

for any such Derivative Works as a whole,

provided Your use, reproduction, and distribution of the Work otherwise complies with the conditions stated in this License.

Should this be understood as a) or as b)?

• a) You may choose a different licence.
• b) You may choose a different licence for your modifications, but unchanged parts of the original work must remain under the Do No Harm Licence.

If it's meant like b), I think it should be clarified more.

[tommaitland]

This is pulled directly from the Apache 2.0 license and therefore I don't think we should change it. See: https://www.apache.org/licenses/LICENSE-2.0