Can a metal cabinet affect the receive signal strength? (yes/no)

The Move up and Move down arrows in the Edit Photo Album dialog box are used to rearrange to order of photographs in the album

Indicate whether the statement is true or false

Which one of the following statements is true about primary keys?

(A) A column of names is usually a good choice for use as a primary key. (B) Only a single record can be used as a primary key. (C) Social Security numbers are never used as a primary key. (D) A primary key is used to uniquely identify records in a table.