D is correct

Correct answer is D

Correct answer is D, and more accurate link is https://help.salesforce.com/s/articleView?id=sf.os_embed_flexcard_inside_another_flexcard.htm&type=5
(passing attribute from parent to child flexcard.

B
https://help.salesforce.com/s/articleView?id=sf.os_pass_data_from_a_child_flexcard_to_a_parent_flexcard.htm&type=5

Correct answer should be D i think, here's the reference : https://trailhead.salesforce.com/content/learn/modules/omnistudio-flexcards-building-and-publishing/work-with-child-flexcards#:~:text=In%20the%20above%20example%2C%20note%20the%20Input%20Map%20(1)%20section.%20The%20child%20FlexCard%E2%80%99s%20data%20source%E2%80%99s%20Input%20Map%20shows%20the%20Id%20(2)%20as%20the%20input.%20The%20Value%20field%20uses%20the%20parent%E2%80%99s%20Record%20Id%20as%20the%20value%20of%20the%20child%E2%80%99s%20contextId%2C%20%7BParent.Id%7D%20(3).%C2%A0