Question

which is recommended but not required to use esw?
pdf viewer
printer
media player
word processing program

Explanation:

ESW (Electronic Software Warehouse) is mainly related to software - related operations. A PDF viewer can be useful for viewing associated documentation or reports related to software in ESW, but is not essential for using ESW itself. A printer is not directly related to using ESW. A media player has no direct connection to ESW. A word - processing program is also not directly relevant to using ESW.

Answer:

A. PDF viewer