I believe the question is asking which of the options is true about a cyber community. In that case, only D is true, as a cyber community, such as facebook or instagram, gives you that ability. The rest of the options only apply to a physical community.
Answer:
D. Software Problem
Explanation:
It could be that the software is bootlooping which will power on and off until its fixed.
I think the answer would be "superscript"
Answer:
b. foreign key
Explanation:
In the database world, a foreign key is a field on one table and a primary key for another table. The purpose of a foreign key is to provide linkages between two or more tables. Given two tables A and B, and making A the point of reference, a primary key is a field that is unique in A while a foreign key is unique in B.
On another hand, a composite primary key is a combination of two or more fields/columns on database table that can be used to uniquely identify each row in the table.
In the database lingua, what we have is a unique key not a distinct key, though the two words are similar in meaning.
A duplicate key is used when an information may be repeatedly entered on a table.
So the correct option is a foreign key.